low carb diet and long term weight loss

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Effect of a low carbohydrate diet on weight loss. Results from randomized trials lasting at least two years [Updated January 2015] Page 1

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This presents sums up the long term clinical trials on low carbohydrate diet

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Page 1: Low carb diet and long term weight loss

Effect of a low carbohydrate diet on weight loss.

Results from randomized trials lasting at least two years

[Updated January 2015]

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Page 2: Low carb diet and long term weight loss

Introduction

• Meta-analyses of short term studies suggest that low carb diets may equally or more effective than usual recommended diet (ie. Low fat diet) in the treatment of obesity (Hession et al. 2008, Nordmann et al. 2006 and Kirk et al. 2008)

• In years 2006-2012 the following low carb diet trials have been published:– Cardillo et al. European Review for Medical and Pharmacological

Sciences 2006

– Shai et al. N Engl J Med 2008

– Sacks et al. N Engl J Med 2009

– Foster et al. Ann Intern Med. 2010

– Guldbrand et al Diabetologia. 2012

www.pronutritionist.net2

Page 3: Low carb diet and long term weight loss

The effects of a low-carbohydrate versus low-fat

diet on adipocytokines in severely obese adults:

three-year follow-up of a randomized trial

Cardillo et al. European Review for Medical and Pharmacological Sciences 2006; 10: 99-106 [Open access]

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The only 3 year trial: a tie

Page 4 Cardillo et al. European Review for Medical and Pharmacological Sciences 2006

Results at 36 months

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Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet

Shai et al. N Engl J Med 2008; 359:229-241 [Open access]

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The first 2 year trial: low carb diet more effective

Page 6 Shai et al. N Engl J Med 2008; 359:229-241

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*) statistically significant from baseline

Schwarzfuchs & Golan Four-Year Follow-up after Two-Year Dietary Interventions NEJM 2012; 367:1373-1374

Four years´ extension of previous Shai study.

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Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein,

and Carbohydrates

Sacks et al. N Engl J Med 2009; 360:859-873 [Open access]

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The 2nd 2 year trial: a tie

Page 9 Sacks et al. N Engl J Med 2009; 360:859-873

”There was no effect on weight loss of carbohydrate level through the target range of 35 to 65 %.”

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Weight and Metabolic Outcomes After 2 Years on a Low-Carbohydrate Versus

Low-Fat DietA Randomized Trial

Foster et al. Ann Intern Med. 2010;153:147-157. [Open access]

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The 3rd 2 year trial: a tie

Page 11 Foster et al. Ann Intern Med. 2010;153:147-157

* P values are for the differences between the 2 groups at each time point.

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In type 2 diabetes, randomisation to advice to follow a low-carbohydrate diet transiently improves glycaemic

control compared with advice to follow a low-fat diet producing a

similar weight loss.

Guldbrand H et al Diabetologia. 2012 May 6. [Open access]

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The 4th 2 year trial: a tie

13 Guldbrand H et al Diabetologia. 2012 May 6

The weight reduction did not differ between the groups (p = 0.33 for all time points)

Low carb diet

Low fat diet

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Summary

Outcome (weight loss vs low fat diet)

Length Note

Cardillo et al. 2006

Equal 3 years No data available for 12 and 24 months

Shai et al. 2008 Low carb better 2 years Mediterranean diet as effective as low carb diet

Sacks et al. 2009 Equal 2 years Protein & Fat modification

Foster et al. 2010

Equal 2 years No data on actual intake of food

Guldbrand et al. 2012

Equal 2 years Primary care intervention in T2D

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Pronutritionist’s discussion• Short term weight loss advantage of low carb diets does not seem to

hold in long term

• No metabolic adverse effects were noted in low carb group. In fact, HDL cholesterol tended to be higer, blood glucose and trglycerides lower in low carb group

• These trials are not included in the meta-analyses of Nordmann (2006), Hession (2008) and Kirk (2008)

• As these randomized trials are longest in their category, they add substantial value to the understanding of the effect of low carb diet

• Results are in line with a recent systematic review which suggested that carbohydrate content of a diet is not directly linked to obesity (Hauner H et al. 2012). Only sugary drinks were shown to be linked to obesity in this review, where as whole grains seemed to be protective

• It will be interesting to see if these trials have any effect on the opinions of low carb advocates like Richard David Feinman, Dr. Michael R Eades, Gary Taubes and like. I doubt.

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Please read the whole papers

Just follow the yellow links on the respective pages

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Follow me

http://twitter.com/pronutritionisthttp://www.facebook.com/pronutritionist

http://www.pronutritionist.net

Reijo Laatikainen, Authorized Nutritionist, MBADietitian

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