A few diet studies...

[_Wolf_]

A few diet studies...


From Alwyn Cosgrove's blog:

I presented most of these in my FitComXpo presentation earlier this month.

One from 2008:

Johnstone et al
Effects of a high-protein ketogenic diet on hunger, appetite, and weight loss in obese men feeding ad libitum.
Am J Clin Nutr.
2008 Jan;87(1):44-55.

This study compared two groups - one following a 4% carbohydrate diet, and one following a 35% carbohydrate diet. After 4 weeks the 4% carbohydrate group had lost 14lbs while the 35% group had lost 9.5lbs. The interesting thing was that the participants were allowed to eat as much food as they wanted within the nutritional guidelines.

They found that in the short term, high-protein, low-carbohydrate ketogenic diets reduce hunger and lower food intake significantly more than do high-protein, medium-carbohydrate nonketogenic diets. Another interesting advantage to reducing carb intake even further (because let's face it - 35% is still reasonably low).

A study from 2003:

Louis-Sylvestre et al.
Highlighting the positive impact of increasing feeding frequency on metabolism and weight management.
Forum Nutr. 2003;56:126-8. Review

This one showed that adults who were accustomed to eating 4 meals a day gained body fat and weight when switched to 3 meals a day (despite calories remaining the same). it seems that meal frequency is an important tool.
One from 1957(!)

Kekwick and Pawan
Metabolic study in human obesity with isocaloric diets high in fat, protein or carbohydrate.
Metabolism. 1957 Sep;6(5):447-60

This study compared THREE hypocaloric diets:

1000 cals at 90% fat: subjects lost 0.9lbs per day
1000 cals at 90% protein: lost 0.6lbs per day
1000 cals – 90% carbs – actually gained slightly (not really significant though).
Conclusion - It's not just about the calories! There does seem to be an advantage to adjusting the macronutrients.
And finally one more from 2003:

Greene, P., Willett, W., Devecis, J., et al.,
Pilot 12-Week Feeding Weight-Loss Comparison: Low-Fat vs Low-Carbohydrate (Ketogenic) Diets," Abstract Presented at The North American Association for the Study of Obesity Annual Meeting 2003, Obesity Research, 11S, 2003, page 95OR.

Three groups on different diets for 12 weeks:
Low fat/low cal (1800 cals per day) diet: Lost on average 17 lbs
Low carb/higher cal (+300) group: Lost on average 20 lbs.
But when they combined low carbs AND low calories (1800 again) - that group lost 23lbs.

Conclusion - it might not be just about the calories - but calories STILL count!
Put these together - reduce carbs, reduce calories, and increase meal frequency to maximize fat loss.
--
AC
www.alwyncosgrove.com

[Eric3237]

You need a whole lot more info than that to compare diets. And it really matters what happens in the long term not in 4 weeks. You cut your carbs that much you can lose water, glycogen, etc....extend it and see what it looks like after a realistic time frame and you'll prob see it a bit differently.

I read that post too and I was a bit taken aback that someone like Cosgrove would present a few isolated "studies" as evidence of something at a presentation.

The interesting thing was that the participants were allowed to eat as much food as they wanted within the nutritional guidelines.

This is the kind of thing I’m talking about. They were “allowed” to eat as much as they wanted. So what? How much DID they eat. Did they eat less because they’re appetites were decreased because of, I don’t know, high fat intake, or ketosis? And it the “weight” loss was an effect of eating less, than it does show that different combos of foods affect appetite but it still comes down to “less calories” which means that in the long term someone not over-eating will have the same results. So there are just too many unanswered questions.

And it guarantee some of the initial weight loss is glycogen related anyway.

[_Wolf_]

Originally Posted by Eric3237

You need a whole lot more info than that to compare diets. And it really matters what happens in the long term not in 4 weeks. You cut your carbs that much you can lose water, glycogen, etc....extend it and see what it looks like after a realistic time frame and you'll prob see it a bit differently.

i think this is the biggest problem with the study. it was WAY too short term. 4 weeks is NOTHING.