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

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

2. 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

3. 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]
Page 3
11

4. Page 4
The only 3 year trial: a tie
Page 4 Cardillo et al. European Review for Medical and Pharmacological
Results at 36 months

5. Weight Loss with a Low-Carbohydrate,
Mediterranean, or Low-Fat Diet
Shai et al. N Engl J Med 2008; 359:229-241 [Open
access]
Page 5
22

6. Page 6
The first 2 year trial: low carb diet
more effective
Page 6 Shai et al. N Engl J Med 2008; 359:229-241

7. 7
*) 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.

8. 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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33

9. Page 9
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 %.”

10. 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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44

11. Page 11
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.

12. 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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55

13. 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

14. 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
www.pronutritionist.net14

15. 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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16. Please read the whole papers
Just follow the yellow links on
the respective pages
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17. Follow me
http://twitter.com/pronutritionist
http://www.facebook.com/pronutritionist
http://www.pronutritionist.net
Reijo Laatikainen, Authorized Nutritionist, MBA
Dietitian
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