Can Low-fat Foods Contribute to Obesity?
A Cornell University study showed people ate an average of
28% more total calories when they ate low-fat snacks as compared
to regular ones.
Wansink, Brian and Pierre Chandon (2006), Can "Low-Fat"
Nutrition Labels Lead to Obesity?, Journal of Marketing Research,
Moderately High Protein Diet Findings
- > weight loss
- > loss of body fat
- > sparing of muscle protein
- > stability of blood sugar
- < triglycerides
Layman DK et al. (2003). A reduced ratio of dietary carbohydrate
to protein improves body composition and blood lipid profiles
during weight loss in adult women. J Nutr.;133:411-417.
Low Carb Diets -vs- Other Diets
Low Carbohydrate diet have been shown to be more effective for
short-term weight loss (less than 6 months to 1 year) than calorie
restrictive diet and/or low fat diets. Improvements in blood
pressure, lipids, fasting glucose, and insulin were also observed.
Brehm BJ, Seeley RJ, Daniels SR, D'Alessio DA (2003). A
randomized trial comparing a very low carbohydrate diet and a
calorie-restricted low fat diet on body weight and cardiovascular
risk factors in healthy women. J Clin Endocrinol Metab. 88(4):1617-23.
Foster GD, Wyatt HR, Hill JO, McGuckin BG, Brill C, Mohammed
BS, Szapary PO, Rader DJ, Edman JS, Klein S (2003). A randomized
trial of a low-carbohydrate diet for obesity. N Engl J Med. May
Samaha FF, Iqbal N, Seshadri P, Chicano KL, Daily DA, McGrory
J, Williams T, Williams M, Gracely EJ, Stern L (2003). A low-carbohydrate
as compared with a low-fat diet in severe obesity. N Engl J Med.
Low Carb Diet Meta Studies
Meta studies performed in
2003 could not find sufficient evidence to make recommendations
for or against the use of low-carbohydrate diets (Bravata 2003).
Meta analysis in 2006 found favorable data to support the efficacy
of Low Carbohydrate diets (Krieger 2006). Krieger et al. (2006)
also noted protein intakes of >1.05 g/kg were associated with
0.6 kg additional fat-free mass retention.
Bravata DM, Sanders L, Huang J, Krumholz HM, Olkin I, Gardner
CD, Bravata DM (2003). Efficacy and safety of low-carbohydrate
diets: a systematic review. JAMA. 9;289(14):1837-50.
Krieger JW, Sitren HS, Daniels MJ, Langkamp-Henken B (2006).
Effects of variation in protein and carbohydrate intake on body
mass and composition during energy restriction: a meta-regression
1. Am J Clin Nutr. 83(2):260-74.
Low Carb Combined with High Protein or High Fat
A hypo-caloric (1433 kcal) low carbohydrate (36% carbs) diet
with either high protein (34% protein, 29% fat) or high monosaturated
fat (18% protein, 45% fat) resulted in similar weight loss, insulin
resistance, and cardiovascular disease risk factors. However,
the high protein diet had less loss of the thermic
effect of feeding. Neither diet had any detrimental effects
on bone turnover or renal function.
Luscombe-Marsh ND, Noakes M, Wittert GA, Keogh JB, Foster
P, Clifton PM (2005). Carbohydrate-restricted diets high in either
monounsaturated fat or protein are equally effective at promoting
fat loss and improving blood lipids. Am J Clin Nutr. 81(4):762-72.
Low Carb versus Very Low Carb
et al 2006 found that a ketogenic low-carbohydrate diet (beginning
with ~5% carbohydrate, 60% fat) and nonketogenic low-carbohydrate
diet (40% carbohydrate, 30% fat) were equally effective in reducing
body weight and insulin resistance. However, ketogenic group
experienced several adverse metabolic and emotional effects such
as higher inflammatory risk (arachidonic acid:eicosapentaenoic
acid ratios in plasma phospholipids) and lower perceptions vigor.
Johnston CS, Tjonn SL, Swan PD, White A, Hutchins H, &
Sears B (2006). Ketogenic low-carbohydrate diets have no metabolic
advantage over nonketogenic low-carbohydrate diets. American
Society for Clinical Nutrition: 83, 5: 1055-1061.
The A TO Z Weight Loss Study
Premenopausal overweight and obese women (mean: age 41, 85
kg) who were randomly assigned to the Atkins diet lost significantly
more weight (-4.7 kg) and had more favorable overall metabolic
effects at 12 months than any other treatment group including
Zone (1.6 kg), LEARN (2.6 kg), and Ornish (2.2 kg).
Gardner CD, Kiazand A, Alhassan S, Kim S, Stafford RS,
Balise RR, Kraemer HC, King AC (2007). Comparison of the Atkins,
Zone, Ornish, and LEARN diets for change in weight and related
risk factors among overweight premenopausal women: the A TO Z
Weight Loss Study: a randomized trial. JAMA. 297(9):969-77.
Low Carb, Low Fat, or Mediterranean Diet
obese subjects (86% male; Mean: age 52, BMI 31) were randomly
assigned to one of three groups for 2 years. Adherence to a study
diet was 95.4% at 1 year and 84.6% at 2 years
- 20g Carbs/day for 2 months
- 120 g per day for weight maintenance
- non-calorie restrictive, urged to use vegetarian sources
of fat and protein
- Average weight loss was 4.7 kg
- Experienced most favorable effects on lipids
- Mediterranean diet (-4.6 kg)
- <35% Fat with olive oil and nuts
- Men 1800 kcal/day
- Women 1500 kcal/day
- Average weight loss was 4.4 kg
- Experienced most favorable glycemic control
- 30% Fat, 10% Saturated Fat
- Men 1800 kcal/day
- Women 1500 kcal/day
- Average weight loss was 2.9 kg
Shai I, et al. (2008). Weight loss with a low-carbohydrate,
Mediterranean, or low-fat diet. N Engl J Med. 359 (3): 229-41.
Protein and Body Weight Regulation
- Protein is more satiating than carbohydrate and fat.
- Animal protein induces a higher thermogenesis
than vegetable protein.
- High-protein diets affect body weight loss positively only
under ad-libitum energy intake conditions, suggesting a resulting
decrease energy intake.
- High protein diets improve body composition and metabolic
- After weight loss, additional protein consumption results
in a significantly lower body weight regain
- due to body composition, satiety, thermogenesis, and energy
- metabolic profile improves further
Westerterp-Plantenga MS (2003). The significance of protein
in food intake and body weight regulation. Curr Opin Clin Nutr
Metab Care. 6(6):635-8.
"Hence the most reasonable treatment of obesity is to
limit the use of non-protein foods and to indulge in hard muscular
Hough T & Sedgwick WT (1906). The Human Mechanism,
Ginn & Company, pg 236.