Journal of BehavioralMedicine, Vol. 10, No. 2, 1987

Sex Differences in Weight Loss Among

Adults with Type II Diabetes Mellitus

Carma A. Heitzmann, _ Robert M. Kaplan, 2'3Dawn K. Wilson, 2 and Jeffery Sandier 4

Accepted for publication."November 30, 1985

The treatment of choice for Type II or non-insulin-dependent diabetes mellitusis a behavioral program for the management of weight. However, compliancewith this lifelong dietary regimen is often poor. In the current investigationmale and female adults wRh diagnosed Type II diabetes were randomly assign-ed to either a behavior modification, a cognitive modification, a cognitive-behavior modification, or a control group. Patients were evaluated in termsof weight, percentage of body fat, and glycosylated hemoglobin measures.Men lost signficantly more weight than women and subjects in the behaviormodification group lost more weight and demonstrated greater decreases indiabetes control than subjects in the cognitive-behavior modification,cogn#ive, and control groups. A significant interaction indicated that diabeticmen may benefit more from behavioral weight reduction programs thandiabetic women. Several explanations for these findings are considered.

KEYWORDS:behavior modification; diabetes; sex differences;weightloss.

This work was supported by Grants K04 HL 00809 and R01 AM 27901 from the National In-stitutes of Health to Robert M. Kaplan.

_Arizona State University, Tempe, Arizona 85287.2Centerfor BehavioralMedicine,San DiegoState University,San Diego, California 92182.3To whom correspondence should be addressed.4San Diego, California.

197

0160-7715/87/0400-0197505,00/0 © 1987 Plenum Publishing Corporation

198 Heitzmann,Kaplan,Wilson,andSandier

INTRODUCTION

Adjustment to a chronic disease often requires difficult changes in life-style. The vast literature on patient compliance indicates that the morenumerous the changes and the more complex and enduring the regimen, themore difficulty patients experience in adhering to their physicians' recom-mendations (e.g., Cohen, 1979; Haynes et al., 1979; DiMatteo and DiNicola,

1982). Diabetes mellitus requires patients, among other things, to adopt com-plex nutritional practices, manage their weight, and monitor their bloodand/or urine glucose levels (Fisher et al., 1982). Consequently, numerousreports have documented that meeting self-care requirements is often dif-ficult for these patients (Watts, 1980).

The specific requirements of diabetes management are dependent uponthe form of the disease. The two most common types of diabetes are TypeI or insulin-dependent diabetes mellitus (IDDM) and Type II or non-insulin-dependent diabetes mellitus (NIDDM) (National Diabetes Data Group, 1979).

Type I diabetes is usually considered to be the more severe form of the disease.It typically begins in childhood and is caused by the cessation of the produc-tion of an adequate supply of insulin by the pancreas. Patients with TypeI diabetes are dependent upon exogeneous insulin to preserve life (Fisher etal., 1982; Kaplan and Atkins, 1985).

Although patients with Type II diabetes are typically not insulin requir-ing, insulin injections or oral medications are sometimes prescribed to cor-rect hyperglycemia (abnormally high blood sugar) (American DiabetesAssociation, 1984). Instead, patients with non-insulin-dependent diabetes areoften encouraged to control their disease through a program of decreasedcaloric intake leading to weight management (Skyler, 1979). In fact,behavioral management is considered the treatment of choice. The ClinicalEducational Program of the American Diabetes Association now advises

physicians to withhold prescriptions of medications until a serious trial ofdiet and exercise has failed (American Diabetes Association, 1984; Rifkin,1984). This follows from the understanding that Type II diabetes is very oftenaggravated by obesity (Fisher et al., 1982) and that 60-90% of all non-insulin-dependent diabetic patients are obese. Weight reduction has been shown toimprove glucose intolerance (Wing et al., 1985). Diabetes, however, as wellas obesity may differentially appear in males and females.

Sex Differences

A number of authors have reported sex differences in illness and mor-

tality rates (Marcus and Seeman, 1981; Wingard, 1984). Although currentvital statistics do reflect a higher incidence of diabetes among men, this sex

SexDifferencesinWeightLoss 199

ratio has evolved only during the last three to four decades. Earlier studies(e.g., Wilkerson and Krall, 1947) showed an excess of female to malediabetics, yet more recent data suggest that this pattern has reversed. Barrett-

Connor and Wingard (1983) offered three hypothese s to account for thechanging sex ratio: changes in diabetic survival, parity, and obesity.

A change in the sex distribution of obesity was the explanation prefer-red by these researchers. Since Type II diabetes is closely linked to obesity,it follows that "diabetes is more prevalent in women in societies where menare leaner than women and more prevalent in men in cultures where the

reverse is true" (Barrett-Connor and Wingard, 1983, p. 267). Interestingly,while women have a higher incidence of obesity than men (Abraham, 1983),

contemporary men are more obese and contemporary women less obese thantheir predecessors (Barrett-Connor and Wingard, 1983). Population studieshave shown that the greatest increase in obesity for men occurs for the agerange 40-59 years. This is the period when Type II diabetes typically hasits onset (Jeffery et al., 1984). Because of the role of obesity in thepathogenesis Type II diabetes, weight loss is a major concern for both malesand females with this condition.

Behavioral Approaches

The most common educational strategy for the management of TypeII diabetes is to provide information. However, there is substantial evidencethat patient knowledge is uncorrelated with metabolic control (Kaplan et al,,1985; Kaplan and Atkins, 1985, Marquis and Ware, 1979). In addition, there

are few experimental evaluations showing the efficacy of education sessionsthat focus on learning factual information. Instead, diabetic patients mustlearn how to control their behavior.

Weight Loss

Behavioral and cognitive-behavioral techniques for weight control, onthe other hand, have produced more impressive results. Although "the resultsof treatment for obesity are remarkably similar and remarkably poor"

(Stunkard, 1959, p. 79), behavioral techniques have repeatedly fared superiorto numerous alternatives (Abramson, 1977; Jeffery et al., 1978). Examplesof behavioral methods for weight loss that may be appropriate for obesediabetic adults are described by Mahoney and Mahoney (1976), Ferguson

(1975b), and Stuart (1971). Typically, behavior modification for weight lossincludes (1) describing the behavior to be controlled, (2) identifying the stimuliwhich typically occur prior to eating, (3) employing behavioral strategies for

200 Heitzmann,Kaplan,Wilson,andSandier

controlling eating behavior, and (4) changing the consequences of eating(Stunkard, 1979). Studies have demonstrated that obese diabetic adults whosuccessfully lose weight may experience improved binding of insulin to recep-tors (Archer et al., 1975) and correcting of hyperinsulinemia (a conditionunique to Type II diabetes in which there is an excess of insulin in blood)(Farrant et al., 1969; Pfieffer, 1974). With weight loss, insulin productionappears to return to normal and there is less insulin resistance (AmericanDiabetes Association, 1984). With adequate weight loss, many patients cancease taking insulin or oral hypoglycemic drugs. For the obese diabetic thereis more than cosmetic benefit from losing weight. Significant weight loss maylead to better control over the disease and, consequently, to an improvedquality of life.

While diet in and of itself may exert an important influence on weightand diabetes management, the combination of a dietary program with exer-cise may produce even more promising results (Dahlkoetter et al., 1979).Despite this, only a few studies have attempted to modify exercise patternsamong sedentary or chronically ill persons (e.g., Martin et al., 1984; Atkinset al., 1984). For the adult with diabetes, consistent moderate exercise maylead to improved regulation of glucose, reductions in weight, and betteroverall regulation of the metabolic condition (Kaplan and Atkins, 1985). Un-fortunately we know relatively little about the benefits of behavioral weightloss programs for men, since the majority of studies employing behaviormodification techniques has utilized either primarily or exclusively femalesubjects [Straw and Terre (1983), Black and Friesen (1983), and Hagen etal., (1976) provide recent examples using exclusively women].

Weight control programs which have included men typically have hadvery low male-to-female ratios, e.g., 11 men to 122 women (Abrams andFollick, 1983) and 14 men to 46 women (Graham et al., 1983). Inaddition, and possibly because of the small number of male participants,data are typically combined for the two groups, a practice that does not deterresearchers and clinicians from determining the efficacy of their programs

but does prevent the comparison of men and women in terms of relativeweight loss. The few studies that have included larger samples of men haveproduced mixed results. Foreyt et al. (1982) accumulated data from 154 menand 494 women in a behavioral weight loss program. They found that men

lost more weight and maintained a greater weight loss than women. In con-trast, Forster and Jeffery (1984) found no difference between the sexes forshort-term weight loss. However, in their study of 55 men and 58 women,women achieved better maintenance of their weight reduction.

Also scarce are reports examining the weight loss of diabetic men andwomen. In fact, it is not unusual for researchers to screen and subsequently

drop from their programs obese individuals who have other health condi-

SexDifferencesin WeightLoss 201

tions such as diabetes, arthritis, and cardiovascular disease (e.g., James andHampton, 1982). Despite this, it has been asserted that obese diabetic pa-tients have eating patterns similar to those of other obese persons.

Implicitly, then, overweight patients with diabetes should respond tobehavioral self-management techniques (Leon, 1976), and a recent

study with 23 diabetic patients has provided data to support this assertion(Rainwater et al., 1982).

Despite the enthusiasm surrounding weight loss programs for patientswith Type II diabetes, there have been remarkably few systematic evalua-tions. Wing (1984) noted that no published study has evaluated the effectsof diabetes weight control programs with a follow-up of greater than 6

\

months. Wing herself has now reported some follow-up data and is cautiously

optimistic. Yet there are many different approaches to these problems andthere is considerable uncertainly about the most appropriate clinical interven-tion. The behavior therapist has many options including traditional behaviormodification, cognitive-behavior modification, and cognitive therapy.

Diabetic patients may enter programs with different motives than clients intraditional weight management studies. Thus, the differential effectivenessof these programs for patients with diabetes must be established. Further,there are few available data on the impact of these programs upon men, since

male subjects have rarely been included in weight management evaluations.In summary, Type II diabetes mellitus is a major public health prob-

lem. Diabetes is the sixth leading cause of death in the United States (Mor-bidity and Mortality Weekly Report, 1984) and is associated with severecomplications including blindness, heart disease, and kidney failure. Weightloss is the treatment of choice for Type II diabetes (American DiabetesAssociation, 1984; Rifkin, 1984), yet we have few data on the likelihood thatpatients will comply with a weight loss program.

In order to investigate these questions, we assigned male and femaleadults with Type II diabetes to different behavioral strategies for weight loss.These strategies were compared to a control group receiving only experimenterattention. The patients were followed over an 18-month period.

METHOD

Subjects

The subjects were 46 Type II, non-insulin-dependent diabetic patients(22 men and 24 women). The subjects ranged in age from 29 to 79 years (M-- 52.94, SD = 12.08). Two female subjects were black and all others werewhite Caucasian. There was considerable range in income and education;

202 Heitzmann, Kaplan, Wilson, and Sandier

however, all but three were high-school graduates and the majority had some

college. The mean body weight of the subjects was 179.79 lb, with a stan-dard deviation of 35.14 lb (men M = 198.71 women M = 159.69). Althoughnone of these individuals is insulin dependent, 60% use insulin or oralhypoglycemic drugs to control persistent hyperglycemia. The remaining sub-jects control their disease solely through diet and exercise. Criteria for beingadmitted to the study included either fasting blood glucose levels higher than140 mg/dl or normal fasting blood sugar but oral glucose tolerance tests thatindicated blood glucose levels exceeding 200 mg/dl at 2 hr after the ad-ministration of a 75-g carbohydrate dose. These values were obtained froma referring physician or determined by our collaborating endocrinologist(J.S.). Each patient was examined by a board-certified specialist in en-docrinology and metabolism who classified the case as Type II diabetesmellitus.

Recruitment and Screening

The subjects were recruited in a variety of ways. Many of the patientswere referred by a local physician specializing in diabetes care. Patients werealso solicited through public service announcements made periodically bylocal radio stations.

The diabetic patients taking part in this study were screened for otherpossible health problems before being allowed to participate. The first ofthese screening procedures was an exercise stress test used to diagnose heartdisease. The treadmill test also provided data on exercise tolerance, restingand exercise heart rate, and resting and exercise blood pressure. Each testwas given by a certified cardiovascular technician under the supervision ofa physician board-certified in internal medicine. The results of these tests pro-vided a baseline measure of exercise tolerance to ensure that it was medical-

ly safe for each individual to participate in exercise regimens.In addition, a doctor's release form was required from each patient's

personal physician. The physician's release gave consent for the subject totake part in the study and listed any restrictions upon the patient's activity.This release form specifically requested information pertaining to possibleheart problems or other diseases that might interfere with the patient's fullparticipation in the program. Those with significant heart or vascular diseasewere excluded from the study.

Intervention Methods

The interventions employed in this study were designed to improve com-

pliance to structured exercise and dietary programs. The study evaluates

SexDifferencesinWeightLoss 203

behavior modification, cognitive modification, and cognitive-behaviormodification programs.

Following pretreatment assessment, subjects were randomly assignedto one of these experimental groups or to a control group. Originally, 55subjects were randomized and 44 completed the 18-month follow-up.Although they did report for the 18-month follow-up, two additional pa-tients provided data for analysis. Attrition was not significantly differentacross groups. In addition, equal proportions of men and women finishedthe study. Computer-generated permutations of the numbers 1 through 4 wereobtained and sealed in envelopes. The envelopes were then numbered sequen-

tially within groups of four, and the experimenter opened an envelope cor-responding to when the subject entered the study, for purposes of treatmentassignment. The numbers 1 through 4 identified the four groups listed below.The behavior modification group (entry N = 13, 18-month N = 10) con-

centrated on self-control procedures and participants were asked to keep dailyrecords of weight, type and amount of food eaten, and events surroundingeating. They were also asked to monitor their daily exercise by recording thetime allocated to exercise, the total time actually spent exercising, and the

place where they exercised. The core of the behavior modification programwas taken from Ferguson's Habits Not Diets (1975a).

The cognitive modification group (entry N = 13, 18-month N = 10)discussed the important role that cognitions play in developing control overbehaviors and positive and negative self-statements. Subjects were instructedto set reasonable goals for themselves and to keep a diary of their self-statements .during eating and exercise. These diaries were then reviewed atlater sessions. Most of the exercises for the cognitive group were derived from

the chapter on Cognitive Ecology by Mahoney and Mahoney (1976).The cognitive-behavior modification group (entry N = 15, 18-month

N = 12) was asked to monitor their diet and exercise behavior in addition

to their self-statements as described above. Subjects in all three experimen-tal groups, as well as the control group, were given dietary advice by aregistered nutritionist and a prescribed exercise regimen based on their exer-cise tolerance tests. Each group met for seven weekly group sessions. Theamount of time spent in these sessions was constant across conditions in orderto control for subject-experimenter exposure time. The average length of each

group meeting was 1.5 hr. Subjects also received home visits during whichthe various diet and exercise self-report forms were presented, as was adescription of the group in which the individual would be participating. In-cluding the office visit and the home visit there were nine sessions with eachpatient.

The relaxation control group (entry N = 14, 18-month N = 12) was

exposed to progressive muscle relaxation training to help them cope withstress. Psychological stress has been identified as a factor which may affect

204 Heitzmann,Kaplan,Wilson,and Sandier

the status of Type II diabetes. Stress is believed to cause hormonal changeswhich result in fluctuations in blood glucose control. Progressive muscle relax-ation is a frequently prescribed self-management technique to combat stress.A study with obese female diabetics employing relaxation trainingdemonstrated that improved glucose tolerance followed such treatment(Surwit and Feinglos, 1982). Hence, there appears to be both empirical andtheoretical justification for using a relaxation procedure with an attentioncontrol group. These individuals were also provided with factual informa-tion about diabetes but no other interventions were used. Three relaxation

control subjects participated in the follow-ups but did not attend the meetings.It is important to emphasize that the relaxation control group was designedto control for attention and did not receive the in-depth personal exercisescharacterized by Surwit and Feinglos (1982).

Follow-ups

Follow-ups were conducted at 3, 6, 12, and 18 months following theonset of the project. Patients were evaluated on several physical measuresin addition to structured interviews. These same measures were employed atthe initial interview.

Physical Measures

Weight. Because men typically weigh more than women and are,therefore, likely to experience greater weight loss simply because they areheavier, the Quetelet Index was used as a measure of relative weight (fora review see Crique et al., 1982). The Quetetet Index was deemed the mostsuitable tool for epidemiological studies because of its correlation with ma-jor cardiovascular risk factors such as age, cholesterol, triglycerides, bloodpressure, etc. This index is the ratio of weight (lb)/height (in.) 2 x 100.

Glycosylated Hemoglobin. With the subject in a seated position, 5 mlof venous blood was drawn from the anticubital vein. The San Diego In-stitute of Pathology received the whole blood to determine glycosylatedhemoglobin according to the Isolab Quick-Sep Kit QS-9100 method.Glycosylated hemoglobin is believed to be an indication of average blood

glucose control over the preceding 90 to 120 days (Nathan et al., 1984). Thus,glycosylated hemoglobin or HbA1 has become a common indicator ofdiabetes control. The normal range extends to 6.5 °70of the total hemoglobin,

with higher levels indicating progressively poorer control of diabetes.Percentage of Body Fat. Percentage of body fat is calculated by

pinching skin folds at the bicep, tricep, subscapular, and suprailiac regions

Sex Differencesin WeightLoss 205

of the body and measuring the skin-fold thickness using Lange calipers. Thevalues are then summed and a standardized table is used to convert this figure

into a percentage.

RESULTS

Comparisons between the subjects in terms of general physical fitnesswere made prior to the interventions. The initial screening test data wereused for this purpose. Analysis of variance revealed that the four experimentgroups were not significantly different for weight, health status, medicineusage, age, percentage fat, or any other variable prior to treatment (see TableI). Men and women did not differ significantly on any of the per-formance or biochemical measures (e.g., predicted maximum heart rate, bloodpressure, etc.). Although the men weighed more than the women [t(44) =

3.81, p < .01], the Quetelet Index was nearly identical for the men (M =3.88) and the women (M = 3.7) [F(1,53) = .001, p > .99]. However, thewomen had a higher initial percentage body fat (M = 49.60, SD = 13.64)than the men (M = 29.67, SD = 11.56) [t(44) = 4.32, p < .01].

A 2 × 4 (sex by experimental group) analysis of variance using theQuetelet Index at the initial visit as a covariate (to control for initial differencesin relative weight among subjects) was performed to examine changes inweight. Weight (in pounds) at the 18-month follow-up served as the depen-dent variable. There was a significant main effect for sex of subject[F1,37) = 4.23, p < .048]. Men lost an average of 8.00 lb, while womengained an average of .083 lb. There was also a significant main effect forgroup [F(3,37) = 3.16, p < .038]. A post hoc analysis using the Tukey Atest indicated that subjects in the behavior modification group lost significant-ly more weight than subjects in the cognitive-behavior modification and con-trol groups (p < .05). A similar analysis of percentage body fat, controlling

TableI. Comparison of Groups at Entrya

WeightQWB HBA_(%) (lb)

Cognitive-behavioral .70 (.06) 11.52 (2.38) 182.44 (34.39)Behavioral .74 (.08) 9.99 (3.04) 184.08 (43.33)Cognitive .74 (.08) 10.17 (2.30) 171.79 (43.11)Control .71 (.08) 10.99 (2.24) 170.00 (29.73)

p (based on ANOVA) .24 .14 .67

aQWB, Quality of Well-BeingScale;HBA_percentageof glycosylatedhemoglobincells, Entries are means and numbers in parentheses arestandard deviations.

206 Heitzmann,Kaplan,Wilson,andSandier

WEIGHTLOSSFORWOMENBROKEN DOWN BY GROUP

0

-5I-.-

O -10_J

CO -15aZ

-20 ---- BEHAVIORMOD.O _ COGNITIVED.. -25 ..... COG. BEHAVIOR

_--- CONTROL

-30

-35 i i i i, /,,/ IOmo 3mo 6mo 12mo"-- 18mo

FOLLOW-UP PERIOD

WEIGHT LOSS FOR MENBROKEN DOWN BY GROUP

5 ....

-5

O3

O -10 \ ,,,_. _ .,...,,.o

CO -15 \ /r" "'_",-, /=" \ / ----BEHAV,OR OD.

_/ _ COGNITIVE

O ..... COG. BEHAVIORD.. -25

------ CONTROL

-30

-35 I I I I // I0mo 3mo 6mo 12mo// 18mo

FOLLOW-UP PERIOD

Fig. 1. Interaction of sex and group assignment.

for initial body fat, showed the same effect for group [F(3,37) = 2.64, p< .05]. However, changes using the Quetelet measure as a dependent variablewere not statistically significant.

There is also evidence that diabetic men may benefit more frombehavioral weight reduction programs than women, as suggested by aborderline significant interaction [F(3,31) = 2.79, p < .057]. Although thisanalysis does not reach the conventional significance level, it indicates atrend in this direction and accordingly another Tukey A test was performedto determine the specifics of the relationship (p < . 10). The interaction ofsex and group assignment is shown in Fig. 1. The top portion gives the datafor women. As the figure demonstrates, all treatment groups lost more weight

than the control group. However, the differences were not statistically signifi-

Sex Differences in Weigh! Loss 207

cant for women and the rank order of the groups was not consistent overtime. The bottom portion of Fig. 1 presents data for men. Men in the behaviormodification group lost a significant amount of weight while in the program(29 lb) and maintained a weight loss of 9 lb over 18 months. Weight lossfor the cognitive group also remained significant through 18 months.However, differences between the cognitive-behavior modification and thecontrol groups were not statistically significant for men. When evaluated forchanges in percentage fat, the interaction was not statistically significant,however, there was a strong trend in the same direction as for the data onweight loss.

Differences between groups for HbA1 were not statistically significant.We have previously reported that changes in glycosylated hemoglobins lagbehind weight loss (Wilson et al., 1985). At the 18-month follow-up menhad experienced significantly greater reductions in HbA1 than women[F(1,37) = 4.31, p < .05]. Although the experimental groups did not differin HbA1 reduction, there was a significant correlation between weight lossat 18 months and reduction in HbA1 (r = .32, p < .05).

DISCUSSION

Reviews of the compliance literature often suggest that there is no rela-tionship between sex of subject and program adherence (e.g., Marston, 1970;Haynes et al., 1979). The present study, in contrast, suggests that there aresex differences for weight loss in patients with Type II diabetes. Men lostsignificantly more weight than women. These findings are consistent withother studies in which men lost more weight than women (Stunkard andMcLaren-Hume, 1959). Stuart and Jacobson (1979) suggested that observeddifferences in weight loss between men and women are often negated by ad-justments for initial body weight. However, the differences we observed re-mained statistically significant after adjustment for obesity (Quetelet Index).These results are also consistent with other evidence suggestive of male/femaledifferences in dietary control and weight loss. In one study in which menand women were asked to make changes in life-style, i.e., alcohol, smoking,obesity, and drug abuse, men did twice as well as women overall and, mostimportantly, were more successful than the women in terms of weight con-trol (Burnum, 1974). Further, a program designed to improve the complianceof patients on hemodialysis resulted in a significantly greater number of menthan women who complied with certain food restrictions (Blackburn, 1977).

Although women in the Stanford Heart Disease Prevention Program hadmore desirable initial eating behaviors, men responded better to instructionand were able to make more changes (Stern et al., 1976). As discussed

208 Heitzmann,Kaplan,Wilson,andSandier

previously, authors often do not report results according to sex of the sub- 'ject. Our data and those cited above suggest that there may be "hidden dif-ferences" between males and females that go unreported in the literature.However, in the few available studies, men seem to be able to achieve greaterweight or dietary changes than women.

Although it is difficult to account for these male/female differences

given the present data, several explanations appear plausible. First, the highermorbidity rate among women (Wingard, 1982) indicates a greater sensitivityof women to physical symptoms. In turn, there are a number of physicalsymptoms which are often related to dieting and weight loss (e.g., fatigue,dizziness, general weakness, and headache). Therefore, women may be morelikely than men to discontinue or not comply with a weight control programsince they are more acutely aware of somatic discomfort. Some evidence forthis argument is provided by the differences found between the heart ratesof men and those of women at the conclusion of the treadmill test. It ap-pears that the men were more likely to exert themselves to a point where theirheart rates were substantially increased (mean heart rate = 160), a level ofexertion typically accompanied by fatigue, weakness, perspiration, etc. Thewomen, on the other hand, were more likely to discontinue the test beforereaching this point (M = 152, t = 1.74, p < .10), thereby minimizing oreliminating any physical discomfort.

The brevity of this treatment program may be partially responsible forthe absence of weight reduction among female subjects. Recent weightmanagement studies have suggested that treatment must extend over a periodof several months, even up to a year, in order for significant effects to be

elicited and maintained (e.g., Wing et al., 1985). The finding that the menin this study were able to benefit from only 7 weeks of intervention may reflectthe specific nature of their weight problem, namely, that weight loss was en-couraged to manage their Type II diabetes. The subjects in this program maybe a distinct group of obese persons whose excess weight poses a greater threatto their personal well-being than it does to their nondiabetic yet obese counter-parts. In short, the factors that contribute to successful weight control maybe somewhat different for the diabetic individual, and treatment (at least

for men) may not have to be as long since initial motivation is likely to beheightened.

Length of treatment may also account for the lowered effectiveness of

the cognitive-behavior therapy program as compared to behavior modifica-tion alone. The seven behavior modification session were devoted to a delinea-

tion of self-control principles and an application of these principles to dietand exercise behaviors. On the other hand, the combined intervention

necessitated a division of time between behavioral and cognitive strategies.A significant portion of the sessions was devoted to instruction in monitor-

SexDifferencesin WeightLoss 209

ing and modifying self-statements. Therefore subjects in the combined groupwere asked to process a greater amount of information in the same limitedamount of time. It is possible that changes in overt behavior may be morereadily achieved after short-term interventions than can modifications inthought processes, particularly with a highly motivated group for whom theconsequences associated with not altering life-style patterns are formidable.The behavior modification group may have provided a sufficient but not over-whelming amount of information leading to changes in dietary and exercisehabits.

In summary, male and female diabetic adults appear to differ in theease with which they lose weight following intervention. Although reviewsof the compliance literature often conclude that there are few sex differencesin medicine-taking compliance, our findings are consistent with several studiesin which males and females are asked to make life-style changes. While themodest number of participants in this study may somewhat limit the

generalizability of the results, it is important to note that the percentage ofmen in this sample is substantially larger than is found in the majority ofpublished weight control studies. In addition, very few studies of weightmanagement with chronically ill patients have been published. A physicalillness, such as diabetes, may provide a greater stimulus for participation.Whether or not these results generalize to men who do not have diabetesremains to be demonstrated.

REFERENCES

Abraham, S. (1983). Obese and overweight adult in the United States. In Vital and HealthStatistics, Set. 11, No. 230. Natl. Center Health Stat., DHHS Publ. (PHS) 83-1680.

Abrams, D. B., and Follick, M. J. (1983). Behavioral weight-loss intervention at the worksite:Feasibility and maintenance. J. Consult. Clin. Psychol. 51(2): 226-233.

Abramson, E. E. (1977). Behavioral approaches to weight control. Behav. Res. Ther. 15: 355-363.American Diabetes Association (1984). Physicians Guide to Type H Diabetes (NIDDM) Diagnosis

and Treatment, ADA, New York.Archer, J. A., Gorden, P., and Roth, J. (1975). Defect in insulin binding to receptors in obese

man: Amehoration with calorie restriction. J. Clin. Invest. 55: 166-174.

Atkins, C. J., Kaplan, R. M., Timms, R. M., Reinsch, S., and Lofback, K. L. (1984). Behavioralexercise programs in the management of chronic obstructive pulmonary disease.J. Consult. Clin. Psychol. 52: 591-603.

Barrett-Connor, E., and Wingard, D. L. (1983). Sex differences in diabetes mellitus. In Gold,E. B. (ed.), The Changing Risk of Disease in Women: An Epidemiological Approach.D. C. Heath, Lexington, Mass., Chap. 20.

Black, D. R., and Friesen, J. G. (1983). Deposit money: A component in a self-directed minimalintervention program for weight control. Behav. Ther. 14: 333-340.

Blackburn, S. L. (1977). Dietary compliance of chronic hemodialysis patients. J. Am. Diet.Assoc. 70: 31-37.

Bray, G. A., Davidson,M. B., andDrenick,E. J. (1972).Obesity:A serioussymptom.Ann.Intern. Med. 77: 779-795.

210 Heitzmann, Kaplan, Wilson, and Sandier

Burnum, J. F. (1974). Outlook for treating patients with self-destructive habits. Ann. Intern.Meal. 81: 387-393.

Cohen, S. J. (1979). New Directions in Patient Compliance, D.C. Health, Lexington, Mass.

Criqui, M. H., Klauber, M. R., Barrett-Connor, E., et al. (1982). Adjustment for obesity instudies of cardiovascular disease. Am. J. Epidemiol. 116: 685-691.

Dahlkoetter, J., Callahan, E. J., and Linton, L. (1979). Obesity and the unbalanced energy

equation: Exercise versus eating habit change. J. Consult. Clin. Psychol. 47(5): 898-905.DiMatteo, M. R., and DiNicola, D. D. (1982). Achieving _atient Compliance: The Psychology

of the Medical Practitioner's Role, Pergamon Press, New York.Farrant, P. C. Meville, R. W. J., and Stewart, G. A. (1969). Insulin release in response to oral

glucose in obesity: The effect of reduction in body weight. Diabetolgia 5: 198-200.Ferguson, J. (1975a). Habits Not Diets, Bull, Palo Alto, Calif.

Ferguson, J. (1975b). Learning to Eat-Behavior Modification for Weight Control, Bull, PaloAlto, Calif.

Fisher, E. B., Delameter, A. M., Bertelson, A. D., and Kirkley, B. G. (1982). Psychologicalfactors in diabetes and its treatment. J. Consult. Clin. Psychol. 50(6): 993-1003.

Foreyt, J. P., Mitchell, R. E., Garner, D. T., Gee, M., Scott, L. W., and Gotto, A. M. (1982).Behavioral treatment of obesity: Results and limitations. Behav. Ther. 13: 153-163.

Forster, J. L., and Jeffery (1984). Gender differences related to weight history, eating patterns,efficacy expectations, self-esteem, and weight loss among participants in a weight reduction

program. Unpublished, University of Minnesota, Minneapolis.Gabbay, K. H., Hasty, K., Breslow, J. L., and Ellison, R. C. (1977). Glycosylated hemoglobins

and long-term blood glucose control in diabetes mellitus. J. Clin. Endocrinol. Metabol.44: 859-864.

Graham, L. E., Taylor, B., Hovell, M. F., and Siegel, W. (1983). Five-year follow-up to abehavioral weight-loss program. J. Consult. Clin. Psychol. 51(2): 322-323.

Hagen, R. L., Foreyt, J. P., and Durham, T. W. (1976). The dropout problem: Reducing attri-tion in obesity research. Behav. Ther. 7: 463-471.

Haynes, R. B., Taylor, D. W., and Sackett, D. L. (1979). Compliance in Health Care, JohnsHopkins University Press, Baltimore.

Heitzmann, C. A., and Kaplan, R. M. (1984). Sex by social support interaction in diabetesmellitus. J. Consult. Clin. Psychol. 52(6): 1087-1089.

James, J. E., and Hampton, B. A. M. (1982). The relative efficacy of directive and non-directivetreatment in behavioral weight control. Behav. Ther. 13: 463-475.

Jeffery, R. W., Wing, R. R., and Stunkard, A. J. (1976). Behavioral treatment of obesity: Thestate of the art. Behav. Ther. 9: 189-199.

Jeffery, R. W., Folsom, A. R., Luekper, R. V., Jacobs, D. R., Gillam, R. F., Taylor, H. L.,and Blackburn, (1984). Prevalence of overweight and weight loss experience. Am. J. Publ.Health 74: 349-352.

Kaplan, R. M., and Atkins, C. J. (1985). The behavioral management of type II diabetes mellitus.In Kaplan, R. M., Criqm, M. H. (eds.), Behavioral Epidemiology and Disease Preven-tion, Plenum, New York.

Kaplan, R. M., Bush, J. W., and Berry, C. C. (1976). Health status: Types of validity andindex of well-being. Health Serv. Res. 11(4): 478-507.

Kaplan, R. M., Chadwick, M. W., and Schimmel, L. E. (1985). Social learning intervention topromote metabolic control in Type 1 diabetes mellitus: Pilot experiment results.Diabetes Care 8: 152-155.

Leon, G. R. (1976). Current directions in the treatment of obesity. Psychol. Bull. 83: 557-558.Mahoney, M., and Mahoney, K. (1976). Permanent Weight Control, W. W. Norton, New York.Marcus, A. C., and Seeman, T. E. (1981). Sex differences in health statistics: A re-examination

of the nurturant role hypothesis. Am. Sociol. Rev. 46:119-123.Marquis, K., and Ware, J. E. (1979). New measures of diabetic patient knowledge, behavior,

and attitudes. Rand Corporation, Santa Monica.Marston, M. V. (1970). Compliance with medical regimens: A review of the literature. Nursing

Res. 19: 312-323.

Sex Differences in Weight Loss 211

Martin, J. E., Dubbert, P. M., Katell, A. D., Thompson, J. K., Raczynski, J. R., Lake, M.,Smith, P. O., Webster, J. S., Sikora, T., and Cohen, R. E. (1984). Behavioral control ofexercise in sedentary adults: studies 1 through 6. J. Consult. Clin. Psychol. 52:795-811.

Morbidity and Mortality Weekly Report (1984). Center for Disease Control, April 24.Nathan, D. M., Singer, D. E., Hurxthal, K., and Goodson, J. D. (1984). The clinical informa-

tion value of the glycosylated hemoglobin assay. N. Engl. J. Med. 310(6): 341-346.National Diabetes Data Group (1979). Classification and diagnosis of diabetes mellitus and other

categories of glucose intolerance. Diabetes 28: 1039-1057.Pfieffer, E. F., (1974). Obesity, islet function and diabetes mellitus. Norm Metab. Res. Suppl.

4: 143-152.

Rainwater, N., Ayllon, T., Fredriksen, I. W., Moore, E. J., and Bonar, J. R. (1982). Teachingself-management skills to increase diet compliance in diabetes. In Stuart, R. B. (ed.),Adherence, Compliance, and Generalization in Behavioral Medicine, Brunner/Mazel,New York.

Rifkin, H. (1984). The state of the art: Type II diabetes. Diabetes Forecast 37(4): 30-32, 67.Skyler, J. S. (1979). Diabetes and exercise: Clinical implications. Diabetes Care 2: 307-311.Stern, M. P., Farquhar, J. W., Macoby, N., and Russell, S. H. (1976). Results of a two-year

health education campaign on dietary behavior. Circulation 54(5): 826-833.Straw, M. K., and Terre, C. (1983). An evaluation on individualized behavioral obesity treat-

ment and maintenance strategies. Behav. Ther. 13: 255-266.Stuart, R. B. (1971). A three dimensional program for treatment of obesity. Behav. Res. Ther.

9: 177-186.

Stuart, R. B., and Jacobson (1979). Sex differences in obesity. In Gomberg, E., andFranks, V. (eds.), Gender and Disorder, Brunner/Mazel, New York.

Stunkard, A. J. (1979). Behavioral medicine and beyond: The example of obesity. In Pomerleau,O. F., and Brady, J. P. (eds.), Behavioral Medicine: Theory and Practice, Williams &Wilkins, Baltimore.

Stunkard, A. J., and McLaren-Hume, M. (1959). The results of treatment of obesity. Arch.Intern. Med. 103: 79-85.

Surwit, R., and Feinglos, M. (1982). Current behavioral research in Diabetes Mellitus. Presentedat the meeting of the society of Behavioral Medicine, Chicago, March.

Verbrugge, L. M. (1976). Females and illness: Recent trends in sex diffeences in the UnitedStates. J. Health Soc. Behav. 17: 387-403.

Watts, F. N. (1980). Behavioral aspects of the management of diabetes mellitus: Education,self-care and metabolic control. Behav. Res. Ther. 18: 171-180.

Wilkerson, H. L. C., and Krall, L. P. (1947). Diabetes in a New England town: A study of3576 persons in Oxford, Mass. JAMA 135: 209-216.

Wilson, D. K., Kaplan, R. M., Heitzmann, C. A., and Sandier, J. (1985). Correlates of weightreduction for patients with Type II diabetes mellitus. Diabetes 34: 206A

Wing, R. (1984). Behavioral approaches to weight control. Presented at the meeting of theAmerican Diabetes Association, Las Vegas, June.

Wing, R. R., Epstein, L. H., Nowalk, M. P., Koeske, R., and Hagg, S. (1985). Behavior change,weight loss, and physiological improvements in Type II diabetic patients. J. Consult.

Clin. Psychol. 53(1): 111-122.Wingard, D. L. (1982). The sex differential in mortality rates: Demographic and behavioral

factors. Am. J. Epidemiol. 115: 205-216.