Diabetes Diet News

13 January 2009

Low-carb, high-protein diet beats low-fat diet for weight loss - again

Results from a systematic review demonstrate, yet again, that low-carbohydrate, high-protein diets are more effective for reducing weight and improving cardiovascular health than are low-fat diets.

Catherine Rolland and colleagues from Robert Gordon University in Aberdeen, UK, carried out a systematic review of 13 randomized, controlled trials including a total of 1222 individuals comparing low-carbohydrate, high-protein diets with low-fat diets.

Inclusion criteria included publication between January 2000 and March 2007, length of at least 6 months, participants aged 18 years and above, and a mean or median body mass index of at least 28 kg/m2.

Of the 13 studies, five lasted for 6 months, six for 12 months, one for 17 months, and one for 36 months. Eleven studies compared low-carbohydrate, high-protein diets with low-fat, high-carbohydrate diets and two compared medium-protein with high-protein diets. Measurements were compared at 6 and 12 months.

At 6 months, weight loss was an average of 4.02 kg greater in the low-carbohydrate, high-protein group than in the low-fat diet group.

At 12 months, the difference between the two groups had reduced, with the low-carbohydrate, high-protein group having lost an average of 1.05 kg more than the low-fat group.

Rolland and team also noted improvements in serum lipids, although these were more mixed, as a significant improvement in high-density lipoprotein and triglycerides was seen favoring the low-carbohydrate, high-protein group up to 12 months, but improvements in total and low-density lipoprotein cholesterol were higher in the low-fat group at 6 months.

A nonsignificant trend toward improvement in diastolic and systolic blood pressure was also observed up to 17 months for the low-carbohydrate, high-protein group.

The researchers conclude in the journal Obesity Reviews that their results show low-carbohydrate, high-protein diets are more effective for weight loss up to 12 months than low-fat diets with unrestricted or high levels of carbohydrates.

They add that although trends toward cardiovascular improvement favoring the low-carbohydrate, high-protein diet were seen in this study, ?more evidence and longer-term studies are needed to assess the long-term cardiovascular benefits from the weight loss achieved using these diets.

But there have already been many studies, both clinical and epidemiologic dating back over 140 years.

For example, a study conducted at the Eduinburgh Royal Infirmary in 1932 with four different diets with the same number of calories but different constituents gave these results in grams of weight lost per day on average:

high-carbohydrate/low-fat diet — 49 grams (Typical 'slimming' diet)

high-carbohydrate/low-protein — 122 grams

low-carbohydrate/high-protein — 183 grams

low-carbohydrate/high-fat — 205 grams (As recommended on this website)



Those were all 1,000 kcals. But obese patients also lost weight at 2,700-kcals - but only on the low-carb high fat diet.

How much more evidence will it take before the disastrous 'healthy eating' experiment is called to a close — and those perpetrating it, and who are responsible for the increasing ill-health in our society, are called to account?

Hession M, et al. Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities. Obes Rev 2009; 10: 36-50 DOI: 10.1111/j.1467-789X.2008.00518.x