Update on Low Carbohydrate Diets: Research and Clinical...
Transcript of Update on Low Carbohydrate Diets: Research and Clinical...
Update on Low Carbohydrate Diets:
Research and Clinical Implementation
Part 1
Eric C. Westman, M.D. M.H.S.
Duke University Medical Center
Durham, North Carolina
Associate Professor of Medicine
Course Director, Medical Management of Obesity
Vice-president, American Society of Bariatric Physicians
Fellow, The Obesity Society
Co-author of The New Atkins for a New You
1
Assumptions About Diets
• Humans must eat 120 grams of carbohydrate daily
• Low carb diets cannot lead to weight loss because
they don’t explicitly restrict calories
• Low carb diets are “high protein” diets
• LCKDs cause “harmful ketosis”
• Low carb diets are “hard to maintain”
• LCKDs diets increase cardiometabolic risk
2
Human Essential Nutrients • Water
• Energy
• Mineral elements – Major: calcium, phosphorus, potassium, sulfur, sodium, chlorine,
magnesium – Trace: iron, iodine, copper, zinc, manganese, cobalt, chromium,
selenium, molybdenum, fluorine, tin, silicon, vanadium
• Amino acids – Isoleucine, leucine, lysine, methionine, phenylalanine, threonine,
tryptophan, tyrosine, valine
• Fatty acids – Linoleic, linolenic
• Vitamins – Water soluble: thiamine (B1), riboflavin (B2), pyridoxine (B6),
cobalamine (B12), niacin, pantothenic acid, folic acid, biotin, lipoic acid, vitamin C
– Fat-soluble: vitamins A, D, K, E
• Other – Inositol, choline, carnitine
Harper AE. Defining the essentiality of nutrients. In Shils ME et al, eds. Modern Nutrition
in Health and Disease. Baltimore, William & Wilkins, 1999, pp 3-10. 3
Daily Carbohydrate Requirements
• “The lower limit of dietary carbohydrate compatible with
life apparently is zero, provided that adequate amounts of
protein and fat are consumed.”
• “The minimal amount of exogenous and endogenous carb
is dependent upon the brain (100-140 g glucose/d).”
• After ketoadaptation, 80% of the CNS energy can be
derived from ketones, leaving 20-28 g glucose/d.
• “Endogenous glucose production rate: 2-2.5 mg/kg/min ~
2.8 – 3.6 g/kg/day. In a 70 kg man, this represents 210-
270 g/day.”
Institute of Medicine, Dietary Reference Intakes, 2008
4
Food
Lipids Carbohydrates Proteins
Fatty acids + glycerol Amino acids
Acetyl coA
Pyruvate
Energy Processing With Carbohydrate
5
Food
Lipids Proteins
Fatty acids + glycerol Amino acids
Acetyl coA
Pyruvate
Energy Processing Without Carbohydrate
6
Effect of Very Low Carbohydrate Diets or Starvation on
Carbohydrate Metabolism
Ref Subjects CHO/Kcal Duration AcAc b-OH-b Glu Insulin
mmol/L mmol/L mg/dl
Phinney 9 20g 28d Pre - 0.07 86 10.7
1983 Lean 30-50 kcal/kg Post 1.6 74 9.0
Langfort 8 < 5% 3d Pre - 0.28 23.0
1996 Lean 32 kcal/kg Post 1.9 10.5
Sharman 20 46g 56d Pre 0.08 90 23.7
2002 Lean 2400 kcal Post 0.28 90 15.6
Atkinson 7 0.5g 42d Pre - - 105 29.2
1985 Obese 1800 kcal Post 85 15.4
Hall 10 Starvation 12d Pre 0.15 0.27 90
1964 Obese Post 1.04 3.97 69
Westman EC. Journal of Clinical Outcomes Management 1999;6:36-40.
Sharman MJ et al. J Nutr 2002;132:1879-1885. 7
Effect of Very Low Carbohydrate Diets on Weight and Lipids
Ref Subjects CHO/Kcal Duration Weight Chol Trig LDL
Larosa 24 0g/? 2 mo. Pre 203.9 205 138 127
1980 Obese Post 187.0 217 93 151
Golay 22 40g/1000 6 wk Pre 235.4 220 150.5 -
1996 Obese Post 173.7 123.9 34.9
Willi 6 25g/675 2 mo Pre 147.8 162 100
1998 Obese Post 121 90
Young 3 30g/3666 9 wk Pre 102.2
1971 Obese Post 86.0
Rabast 14 40g/1340 4 wk Pre 240.5
1981 Obese Post 214.1
Rabast 25 25g/1000 1 mo Pre 245 230
1978 Obese Post 204 134
Westman EC. Journal of Clinical Outcomes Management 1999;6:36-40. 8
Effect of Very Low Carbohydrate Diets on Weight and Lipids
Ref Subjects CHO/Kcal Duration Weight Chol Trig LDL
Rickman 12 7g/1400 7-17d Pre 139.5 215 131 -
1974 Lean Post 131.6 248 116
Azar 6 1g/2000 4d Pre 150.0 245.2 - -
1963 Lean Post 143.5 284.3
Phinney 9 20g/? 4 wk Pre - 169 91 -
1983 Lean Post 208 79
Newbold 7 ?/? 3-18 mo Pre 263.0 113.0
1988 ? Post 189.3 74.7
Westman EC. Journal of Clinical Outcomes Management 1999;6:36-40.
9
Assumptions About Low Carbohydrate,
High Fat Diets
• Humans must eat 120 grams of carbohydrate daily
• Low carb diets cannot lead to weight loss because
they don’t explicitly restrict calories
• Low carb diets are “high protein” diets
• LCKDs cause “harmful ketosis”
• Low carb diets are “hard to maintain”
• LCKDs diets increase cardiometabolic risk
10
Low Carbohydrate Ketogenic Diet Program
Over Six Months: Pilot Study
51
overweight
volunteers
Low Carbohydrate Diet
instruction
+ group meetings
+ exercise recommendation
+ nutritional supplements
Westman et al. Am J Med 2002;113:30-36. 11
Pilot Low Carb Study:
Weight loss over 6 months
-14
-12
-10
-8
-6
-4
-2
0
Wk 0 Wk 2 Wk 4 Wk 6 Wk 8 Wk
10
Wk
12
Wk
16
Wk
20
Wk
24
Duration of Intervention
Me
an
Pe
rce
nt
Ch
an
ge
in
Bo
dy
We
igh
t (s
em
)
* p < 0.001 comparing Week 0 to Week 24 (n=41).
Change = - 10.3%
Westman et al. Am J Med 2002;113:30-36. 12
Very Low Carb Diet Program vs. Low Fat Diet
Randomized Controlled Trial
120
overweight,
hyperlipidemic
volunteers
R
Low Fat, Low Calorie Diet
+ group meetings
+ exercise recommendation
Low Carbohydrate Diet (no
mention of Calories)
+ group meetings
+ exercise recommendation
+ nutritional supplements
Yancy et al. Ann Intern Med 2004;140:769-777. 13
Percent Change In Body Weight
* p < 0.0001, for within-group change from Baseline to Week 24 for each diet group.
† p = 0.0002, for comparison between diet groups at Week 24.
-16
-14
-12
-10
-8
-6
-4
-2
0
Wk
0
Wk
2
Wk
4
Wk
6
Wk
8
Wk
10
Wk
12
Wk
16
Wk
20
Wk
24
Duration of Intervention
Mean
(S
EM
) %
Ch
an
ge i
n B
od
y W
t
Low Fat
Low Carb
-9.3%*
-14.2%*†
14
Assumptions About Low Carbohydrate,
High Fat Diets
• Humans must eat 120 grams of carbohydrate daily
• Low carb diets cannot lead to weight loss because
they don’t explicitly restrict calories
• Low carb diets are “high protein” diets
• LCKDs cause “harmful ketosis”
• Low carb diets are “hard to maintain”
• LCKDs diets increase cardiometabolic risk
15
Diets, Carbohydrates and Calories
Atkins Induction
Zone Diet
Typical American Diet
Protein Power
CHO Grams/day
20
0
50
100
200
300
Calories/day
2000 1000
(Ketonuria)
Mediterranean Diet
Atkins Maintenance
Very Low Fat Diet
Low Glycemic Index Diet
Diabetes Solution Low Carbohydrate Ketogenic Diet
16
Six-month Pilot Study:
Diet Composition
Composition
Mean Daily Intake
% of Daily Caloric Intake
Protein 113.8 g 32.1
Fat 95.5 g 59.6
Carbohydrate 22.3 g 6.5
Calories 1427.3 kcal
Westman et al. Am J Med 2002;113:30-36.
17
LCKD vs. LFD Diet Composition
Diet Component
Low Fat
(n=7)
Low Carb
(n=13)
Protein 73g (18%) 109g (30%)
Fat 54g (31%) 98g (60%)
Carbohydrate 201g (51%) 35g (10%)
Energy 1588 kcal 1472 kcal
* Food records are from the entire 6 months 18
Low Carbohydrate Diet Composition
0
50
100
150
200
250
300
350
net carb fiber protein fat
gm/d
Usual Diet (3111 kcal/d)
Low Carb (2164 kcal/d)
Boden G et al. Effect of a low-carbohydrate diet on appetite, blood glucose
levels, and insulin resistance in obese patients with type 2 diabetes. Ann Intern
Med 2005;142:403-411. 19
Assumptions About Low Carbohydrate,
High Fat Diets
• Humans must eat 120 grams of carbohydrate daily
• Low carb diets cannot lead to weight loss because
they don’t explicitly restrict calories
• Low carb diets are “high protein” diets
• LCKDs cause “harmful ketosis”
• Low carb diets are “hard to maintain”
• LCKDs diets increase cardiometabolic risk
20
The Role of Ketones
• Ketone bodies: molecules that deliver energy
• Ketones can be used by all cells except
erythrocytes, cornea, lens, retina, renal medulla
• Ketone levels increase when dieting – Fed state 0.1 mmol/L
– Overnight fast 0.3 mmol/L
– Low-carb ketogenic diet 1–3 mmol/L
– > 20 days fasting 10 mmol/L
– Diabetic ketoacidosis 25 mmol/L
• Serum pH did not decrease below 7.37 in a study
performing arterial blood gas analyses
Meckling KA, Can J Physiol Pharmacol, 2002; Coleman MD, J Am Diet Assoc, 2005; Yancy WS, Eur J Clin Nutr, 2007
21
Metabolism Society, Spring 2011
Conference on Ketone Bodies
• Review of Biochemistry of Ketone Bodies
• Ketone Body Effects on Cardiac Energetics and Glycolytic
Flux
• Ketone Bodies and Cancer
• Human Keto-adaptation: Physiology and Function
• Anti-ketogenic Effect of Insulin and Dietary Carbohydrate
• Clinical Treatments using Nutritional Ketosis
• The Ketogenic Diet for Epilepsy
22
Assumptions About Low Carbohydrate,
High Fat Diets
• Humans must eat 120 grams of carbohydrate daily
• Low carb diets cannot lead to weight loss because
they don’t explicitly restrict calories
• Low carb diets are “high protein” diets
• LCKDs cause “harmful ketosis”
• Low carb diets are “hard to maintain”
• LCKDs diets increase cardiometabolic risk
23
Low Carbohydrate Internet-based
Support Group Survey
• Active Low-Carber Forum is an on-line support group started in
2000 and in 2008 had 86,000
• An anonymous 2-item survey was posted to describe the
attitudes and behaviors of people following low carbohydrate
diets
• Survey respondents (n=2000) were predominantly female,
overweight, and following the Atkins diet or some variation of it
• Over 1400 claimed to have used a low carb diet to lose and
maintain at least a 30 pound weight loss
• 28% of respondents reported that their doctor was initially neutral
but supportive after favorable results were obtained
Feinman RD, Vernon M, Westman EC. Nutrition Journal 2006;5:26. 24
Low Carbohydrate Diet Are Very Popular
in Sweden (Google Searches for Popular Diets in Sweden 2008-present)
Low Carbohydrate High Fat
Low Glycemic Index
Weight Watchers
(Andreas Eenfeldt, www.kostdoktorn.se) 25
Assumptions About Low Carbohydrate,
High Fat Diets
• Humans must eat 120 grams of carbohydrate daily
• Low carb diets cannot lead to weight loss because
they don’t explicitly restrict calories
• Low carb diets are “high protein” diets
• LCKDs cause “harmful ketosis”
• Low carb diets are “hard to maintain”
• LCKDs diets increase cardiometabolic risk
26
Effect on Serum Lipids
Variable Baseline Wk8 Wk16 Wk24 Change
mg/dl mean mean mean mean
Cholesterol 214 201 201 203 -6%*
Triglycerides 130 82 75 74 -43%*
LDL 136 136 128 126 -7%*
HDL 52 49 58 62 +16%*
Chol/HDL 4.3 4.3 3.6 3.4 -21%*
Westman et al. Am J Med 2002;113:30-36. 27
Effects on Serum Lipids
Low Fat (n=32) Low Carb (n=44)
Variable
(mg/dl)
Week
0
Week
24 Change
Week
0
Week
24 Change
Cholesterol 233.8 220.7 -6%* 245.4 236.0 -4%
Triglyceride 184.0 144.4 -22%* 167.3 86.0 -49%*†
LDL-C 144.9 139.8 -4% 157.3 158.4 +1%
HDL-C 54.1 52.8 -2% 54.3 60.0 +11%*†
Chol/HDL 4.4 4.3 -5% 4.8 4.1 -15%*†
Trig/HDL 3.6 2.9 -18% 3.3 1.7 -49%†
* p < 0.01, for within-group changes from Baseline. † p < 0.05 for between-groups comparisons.
28
Effect on Fasting Lipid Subclasses
0
20
40
60
80
100
120
140
Larg
e VLD
L
Interm
ed V
LDL
Small V
LDL
IDL
Larg
e LD
L
Interm
ed LDL
Small L
DL
Larg
e HDL
Small H
DL
mg
/dl
Baseline (n=36)
Week 6 (n=36)
Week 12 (n=36)
Week 24 (n=36)
0
20
40
60
80
100
120
140
Larg
e VLD
L
Inte
rmed
VLD
L
Sm
all V
LDL
IDL
Larg
e LD
L
Inte
rmed
LDL
Sm
all L
DL
Larg
e HDL
Sm
all H
DL
mg
/dl
Baseline (n=27)
Week 6 (n=27)
Week 12 (n=27)
Week 24 (n=27)
LOW CARBOHYDRATE DIET PGM LOW FAT DIET GROUP
*
*
*
*
* p < 0.05 for comparison between groups
Westman et al. Int J Cardiol 2006;110:212-216. 29
Effect on Fasting Lipid Subclasses
0
0.5
1
1.5
2
2.5
3
Larg
e VLD
L
Interm
ed V
LDL
Small V
LDL
Larg
e LD
L
Small L
DL
Larg
e HDL*
10
Small H
DL*
10
LDLP
*100
Baseline (n=43)
Week 24 (n=43)
0
0.5
1
1.5
2
2.5
3
Larg
e VLD
L
Inte
rmed
VLD
L
Sm
all V
LDL
Larg
e LD
L
Sm
all L
DL
Larg
e HDL*
10
Sm
all H
DL*
10
LDLP
*100
mg
/dl
Baseline (n=35)
Week 24 (n=35)
LOW CARBOHYDRATE DIET PGM LOW FAT DIET GROUP
*
*
*
*
Seshadri et al. Am J Med 2004;117:398-405.(Subanalysis of Samaha, Stern papers) * p < 0.05 for comparison between groups
*
30
Outpatient LCKD Randomized Controlled Trials: Design
Reference Design Setting Patients Duration Visits
Sondike 2003 RCT Clinic Healthy
teens 3m q2Wk
Brehm 2003 RCT Clinic Healthy
adults 6m
q2Wk x 6, then @
6mo
Samaha 2003
Stern 2004 RCT Clinic
Outpt
adults 6m 12m
qWk x 4, then
monthly
Foster 2003 RCT Clinic Healthy
adults 12m
q2Wk x 2, q4Wk x 4, then Wk 26, 34, 42, 52
Yancy 2004 RCT Clinic Healthy
adults 6m
q2Wks x 6, then
monthly
Brinkworth
2009 RCT Clinic
Healthy
adults 12 m
q2Wks x 4, then
monthly
Nordmann et al. Arch Intern Med 2006;166:285-293. 31
Low Fat Low Carbohydrate
Ref Duration Weight LDL Trig HDL Weight LDL Trig HDL
Sondike 3 mo -4.1kg -17%* -6% +2% -9.9kg* +4% -48%* +4%
n=30
Brehm 6 mo -3.9kg† -5% +2% +8% -8.5kg*† 0% -23%* +13%
n=42
Samaha/ 6 mo -1.9kg† +3% -4% -2% -5.8kg*† +4% -20%* 0%
Stern 12 mo -3.1kg -3% +2% -12% -5.1kg +6% -29% -2%
n=132
Foster 6 mo -5.3kg† -3% -13% +4% -9.7kg*† +4% -21% +20%*
n=63 12 mo -4.5kg† -6% +1% +3% -7.3kg† +1% -28%* +18%*
Yancy 6 mo -6.5kg -3% -15% -1% -12.0kg* +2% -42%* +13%*
n=119
Brinkworth 12 mos -11.5kg +3% -12% 0% -14.5kg +3% -35% +21%
N=40
Outpatient LCKD RCTs: Weight Loss and Serum Lipids
* p<0.05 for between-groups comparison
32
2 months (“efficacy”)
Group n kcal/d CHO PRO FAT Weight LDL Trig HDL L/H
Atkins 40 1736 137g 93.5 89.5 -3.6 kg +1.3 -32.3 +3.2 -0.18
Zone 40 1434 157 90.4 54.5 -3.8 kg -9.7 -54.1 +1.8 -0.33
WWatchers 40 1615 191 80.5 54.5 -3.5 kg -12.1 -9.2 -0.2 -0.42
Ornish 40 1393 230 70.0 27.5 -3.6 kg -16.5 -0.4 -3.6 -0.21
Popular Diet Effects on Weight Loss and Cardiac Risk Factors
Dansinger ML et al. JAMA 2005;293:43-53.
12 months (“effectiveness”)
Group n kcal/d CHO PRO FAT Weight LDL Trig HDL L/H
Atkins 40 1886 190g 86.0 80.5 -2.1 kg -7.1 -1.2 +3.4 -0.39
Zone 40 1757 173 90.4 71.5 -3.2 kg -11.8 -2.5 +3.3 -0.52
WWatchers 40 1832 208 82.5 64.0 -3.0 kg -9.3 -12.7 -3.4 -0.55
Ornish 40 1819 218 76.5 64.0 -3.3 kg -12.6 +5.6 -0.5 -0.31
“To approximate the realistic long-term sustainability of each diet, we asked participants to
follow their dietary assignment to the best of their ability to their 2 month assessment, after
which time we encouraged them to follow their assigned diet according to their own self-
determined interest level.”
33
2 months (“efficacy”)
Group n kcal/d CHO PRO FAT Weight LDL Trig HDL DBP
Atkins 77 1381 ~62g 97 84 -4.3 kg +2.3 -52.3 -0.4 -2.9
Zone 79 1455 152 87 57 -2.0 kg -5.3 -24.8 -0.5 -2.1
LEARN 79 1476 180 73 49 -2.8 kg -7.3 -17.2 -3.8 -1.4
Ornish 76 1408 220 60 33 -2.8 kg -10.1 -10.9 -5.3 -0.4
Popular Diet Effects on Weight Cardiac Risk Among Women
Gardner CD et al. JAMA 2007;297:969-977.
12 months (“effectiveness”)
Group n kcal/d CHO PRO FAT Weight LDL Trig HDL DBP
Atkins 77 1599 ~140g 84 78 -4.5 kg +0.8 -29.3 +4.9 -4.4
Zone 79 1594 179 80 62 -1.5 kg 0 -4.2 +2.2 -2.1
LEARN 79 1654 194 79 61 -2.5 kg +0.6 -14.6 -2.8 -2.2
Ornish 76 1505 195 68 50 -2.4 kg -3.8 -14.9 0 -0.7
“Each diet group attended 1-hour classes led by a registered dietician once per week for 8
weeks and covered approximately one eighth of their respective books per class...Efforts to
maximize retention included email and telephone reminders…and incentive payments.”
34
Effect of Diet Programs on Metabolic Syndrome Parameters
From Baseline to 12 Months
Atkins Zone LEARN Ornish P
(n=77) (n=79) (n=79) (n=76) value
BMI, kg/m2 -1.65 -0.53 -0.92 -0.77 .01
Waist-hip ratio -0.019 -0.013 -0.009 -0.012 .10
HDL-C, mg/dL +4.9 +2.2 +2.8 0.0 0.002
Triglycerides, mg/dL -29.3 -4.2 -14.6 -14.9 0.01
Non-HDL-C, mg/dL -5.1 -0.5 -4.0 -6.8 0.36
Insulin, mU/mL -1.8 -1.5 -1.8 -0.2 0.17
Glucose, mg/dL -1.8 -1.6 +0.5 -0.8 0.54
Diastolic b.p., mmHg -4.4 -2.1 -2.2 -0.7 0.009
Systolic b.p., mmHg -7.6 -3.3 -3.1 -1.9 <0.001
Gardner CD et al. JAMA 2007;297:969-977. 35
Re-examination of the A to Z Study [Gradner et al. JAMA 2007]
Women divided into tertiles based on insulin resistance
Weight loss at 12 mo:
Gardner, C.D., et al., Insulin Resistance - An Effect Moderator of Weight Loss
Success on High vs. Low Carbohydrate Diets. Obesity, 2008. 16: p. S82.
Low Carb Low Fat
Insulin
Resistant
Insulin
Sensitive -11.7 lbs
-11.9 lbs -3.3 lbs
-9.0 lbs
Simply put, insulin
resistance strongly
influences how we
respond to different diets
Validates the concept
that insulin resistance is
essentially an expression
of carbohydrate
intolerance
36
Carbohydrate Restriction Treats
Metabolic Syndrome
• Volek JS, Feinman RD. Carbohydrate restriction improves the features of
Metabolic Syndrome: Metabolic syndrome may be defined by the
response to carbohydrate restriction. Nutr Metab 2005;2:31.
• Feinman RD, Volek JS. Carbohydrate restriction as the default treatment
for type 2 diabetes and metabolic syndrome. Scand Cardiovasc J
2008;42:256-63.
• Accurso A et al. Dietary carbohdyrate restriction in type 2 diabetes
mellitus and metabolic syndrome: time for a critical appraisal. Nutr
Metab 2008;5:9.
• Volek JS, Fernandez ML, Feinman RD, Phinney SD. Dietary carbohydrate
restriction induces a unique metabolic state positively affecting
atherogenic dyslipidemia, fatty acid partitioning, and metabolic
syndrome. Prog Lipid Res 2008;47:307-18.
• Volek JS et al. Carbohydrate restriction has a more favorable impact on
the metabolic syndrome than a low fat diet. Lipids 2009;44:297-309.
37
Low Carb vs. Low Fat Diet + Orlistat
Study Design
146 overweight VA outpatient volunteers
Low Fat Diet + Orlistat
• group meetings for 48 wks
• exercise recommendation
• multivitamin daily
• Orlistat 120 mg three times a day
Low Carb Ketogenic Diet
• group meetings for 48 wks
• exercise recommendation
• multivitamin daily
R
Yancy, Arch Int Med, 2009. 38
Mean % Weight Change Over Time*
n= 74 71 66 65 60 61 69 61 52 53 46 54
65
n= 72 64 58 58 51 50 57 48 43 54 41 40
57
Low Carbohydrate Diet
Orlistat + Low Fat Diet
39
Change in Blood Pressures at 3 Time points
Change in Blood Pressure by Treatment Arm
-7
-6
-5
-4
-3
-2
-1
0
1
2
SBPDBP
SBPDBP
LCKD O+LFDΔmmHg
Δ at 4 weeks
Δ at 24 weeks
Δ at 48 weeks
4 wks (-0.5 v.+0.1; p<.001)
24 wks (-3.0 v.+0.7; p<.001)
48 wks (-5.9 v.+1.5; p<.001) 40
Facts About Low Carbohydrate, High Fat
Diets
• Carbohydrate is not an essential nutrient
• Low carb diets lead to weight loss because
abnormal hunger/appetite goes away
• Low carb diets are adequate protein diets
• Nutritional ketosis is a marker of burning fat
• For many people low carb diets are easy to follow
• LCKDs diets reduce cardiometabolic risk by
addressing the metabolic syndrome
41
Saturated Fat
Saturated Fat
Metabolic Processing of Saturated Fat
Saturated Fat Burned
as Fuel
Saturated Fat Burned
as Fuel
Low Carbohydrate
Diet (45 g CHO/d)
Low Fat Diet
(208 g CHO/d)
Saturated Fat Synthesis
Saturated Fat Intake (12 g/d)
Saturated Fat Synthesis
Saturated Fat Intake (36 g/d)
Forsythe et al. Lipids. 43(1):65-77, 2008 42
Does Insulin Reduction Explain the Lack of
Rise in Serum Cholesterol?
Kennedy AR et al. A high fat, ketogenic diet induces a unique metabolic state in
mice. Am J Physiol Endocrinol Metab 2007, February 13. 43
Diabetic Diet in the Pre-Insulin Era
1914-1921
“Quantity of food required by a severe diabetic patient weighing 60
kilograms”*
Food Calories
Carbohydrate 10 grams 40
Protein 75 grams 300
Fat 150 grams 1,350
Alcohol 15 grams 105
1,795
“Strict diet”: Meats, poultry, game, fish, clear soups, gelatin, eggs, butter,
olive oil, coffee, tea
* Osler W, McCrae T. The Principles and Practice of Medicine. NY: Appleton and Co., 1923.
Allen FM. Protein diets and undernutrition in treatment of diabetes. JAMA 1920;74:571-577.
Newburgh LH, Marsh PL. The use of a high fat diet in the treatment of diabetes mellitus. Arch Int Med
1921;27:699-705. 44
Fat
Liver
Large LDL
Chylomicrons
Cells Atherosclerosis?
Thoracic Duct Superior Vena Cava
Triglycerides
Lymphatics
Triglyceride
Diet: Lipids
Observed Very Low Carb Diet
45
Fat
Small LDL
Carbohydrate
VLDL
Liver
LDL
Chylomicrons
Cells Atherosclerosis
Thoracic Duct Superior Vena Cava
Simple sugars
Portal Vein
Triglyceride
Sugar
Triglycerides
Lymphatics
Triglyceride
Diet: Lipids
Observed Mixed Diet
LDL
46
Weight Loss, Improvements in Lipids
A 50 year old white female with obesity (BMI = 31.3) wants to lose
weight.
Fasting lab tests:
Date BMI Wt (lbs) Chol Trig LDL HDL Glucose
6/10 31.3 178 245 247 141 54 92
Initiation of Carbohydrate Restricted Diet
8/10 29.1 164
2/11 24.5 141
5/11 23.5 138 209 46 119 81 88
She asks, “Why wasn’t I given this option before? I was just given the
options of medications.” 47
Summary
• Instructing people to limit carbohydrate grams leads
to a spontaneous reduction in caloric intake (without
explicitly limiting calories) and: – Loss of body weight
– Improvements in fasting serum lipid profiles (triglyceride,
HDL, chol/HDL ratio)
– Improvement in systolic blood pressure
– Reduction in waist circumference
• Low carbohydrate diets can be used in the clinical
setting by trained practitioners
• A low carbohydrate diets is the preferred diet for
metabolic syndrome
48