Diet, Nutrition and SupplementationPost here for supplement reviews or nutritional advice. If you're trying to get "ripped abz" THIS is where you should be.
The article doesn't say a low GI diet is better than high protein. It's says is "equivalent." What it doesn't talk about is what were the composition of those diets. "High protien" and "Low GI" could mean very different things to different people. I'm going to see if I can track down the original study...
Human Nutrition Unit, University of Sydney, Sydney, Australia.
BACKGROUND: Despite the popularity of low-glycemic index (GI) and high-protein diets, to our knowledge no randomized, controlled trials have systematically compared their relative effects on weight loss and cardiovascular risk. METHODS: A total of 129 overweight or obese young adults (body mass index, > or =25 [calculated as weight in kilograms divided by the square of height in meters]) were assigned to 1 of 4 reduced-fat, high-fiber diets for 12 weeks. Diets 1 and 2 were high carbohydrate (55% of total energy intake), with high and low GIs, respectively; diets 3 and 4 were high protein (25% of total energy intake), with high and low GIs, respectively. The glycemic load was highest in diet 1 and lowest in diet 4. Changes in weight, body composition, and blood chemistry profile were studied. RESULTS: While all groups lost a similar mean +/- SE percentage of weight (diet 1, -4.2% +/- 0.6%; diet 2, -5.5% +/- 0.5%; diet 3, -6.2% +/- 0.4%; and diet 4, -4.8% +/- 0.7%; P = .09), the proportion of subjects in each group who lost 5% or more of body weight varied significantly by diet (diet 1, 31%; diet 2, 56%; diet 3, 66%; and diet 4, 33%; P = .01). Women on diets 2 and 3 lost approximately 80% more fat mass (-4.5 +/- 0.5 [mean +/- SE] kg and -4.6 +/- 0.5 kg) than those on diet 1 (-2.5 +/- 0.5 kg; P = .007). Mean +/- SE low-density-lipoprotein cholesterol levels declined significantly in the diet 2 group (-6.6 +/- 3.9 mg/dL [-0.17 +/- 0.10 mmol/L]) but increased in the diet 3 group (+10.0 +/- 3.9 mg/dL [+0.26 +/- 0.10 mmol/L]; P = .02). Goals for energy distribution were not achieved exactly: both carbohydrate groups ate less fat, and the diet 2 group ate more fiber. CONCLUSION: Both high-protein and low-GI regimens increase body fat loss, but cardiovascular risk reduction is optimized by a high-carbohydrate, low-GI diet.
PMID: 16864756
25% isn't even that high protein. I'm curious what the fat %s are for the studies. I don't have access to read the whole study (and I don't know if I could even read one...), but without details it's hard to dispute anything. I'm guessing we could, knowing more about the content of the diet.
For instance, while a low-GI diet sounds good on paper, what does it mean? In the "high" P group, they might have had to bump up the fat, or the C would hardly change percentages at all. What did they add in, extra salad dressing made with soybean oil? Extra omega-6s aren't going to do wonders for your "cardiovascular risk." Who knows?
Also, the abstract leaves out the fat loss results of women for Diet 4, unless I'm just not seeing it.
I hate studies. Perhaps the pessimist in me sees too many possible holes.
Research on Low Glycemic Index Diets
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