High Protein or High Fat Diets cause more weight loss than High Carb: 18 lbs vs 19 lbs vs 13 lbs

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Thursday, September 22, 2005 8:35 am Email this article
High-protein diets such as "The Zone Diet" and high-fat diets such as "The Atkins Diet" cause greater weight loss than high-carbohydrate diets such as "The Ornish Diet" and others such as the ones recommended by many national and international organizations according to study by Professor Jim I. Mann from the University of Otago in Dunedin, New Zealand and some colleagues. WEIGHT LOSS AFTER 6 MONTHS

Weight loss after 6 months: high-protein vs high-fat vs high-carb:: 18 lbs vs 19 lbs vs 13 lbs

Those in the high-protein diet group lost 17.6 pounds in the first six months compared to 18.7 pounds for those in the high-fat diet group and 13 pounds for those in the high-carbohydrate diet group.

Weight loss after 6 months: high-protein vs high-fat vs high-carb:: 8.5% vs 8.7% vs 6%

As a percent of body weight, weight loss after six months was 8.5 percent for the high-protein diet group versus 8.7 percent for the high-fat diet group and 6 percent the high-carbohydrate diet group.

Body weight after 6 months

Body weight decreased from 206 pounds to 189 pounds in the high-protein group, from 214 pounds to 195 pounds in the high-fat group, and from 215 pounds to 202 pounds in the high-carbohydrate group.

 

WEIGHT LOSS AFTER 1 YEAR

Weight loss after 1 year: high-protein vs high-fat vs high-carb:: 15 lbs vs 12 lbs vs 10 lbs

After one year, the average weight loss was 14.5 pounds for the high-protein group versus 11.9 pounds for the high-fat group and 9.7 pounds for the high-carbohydrate group.

Weight loss after 1 year: high-protein vs high-fat vs high-carb:: 7% vs 5.6% vs 4.5%

After one year, average weight loss as a percent body weight was 7 percent for the high-protein group versus 5.6 percent for the high-fat group and 4.5 percent the high-carbohydrate group.

Body weight after 1 year

Body weight had decreased from an average of 206 pounds to 192 pounds in the high-protein group, from 214 pounds to 205 pounds in the high-fat group, and from 215 pounds to 205 pounds in the high-carbohydrate group.

 

DROUPOUTS

Fewer dropouts in the high-protein group than the high-carb or high-fat groups: 7% vs 25%

People assigned to the high-protein diet were less likely to drop out of the study also.

Only 7 percent of people in the high-protein diet group dropped out after one year compared to 25 percent for people in both the high-fat group and 25 percent for people in the high-carbohydrate group.

This suggests that that a high-protein diet is easier for people to try and follow—less restricting or more palatible—than either the the high-carb or high-fat diets.

 

SUBJECTS

Subjects: 96 insulin-resistant women

The study involved 96 insulin-resistant obese women.

 

DIET COMPOSITIONS

High Protein Diet: 30% Protein, 30% Fat, 40% Carbs

The high-protein group was instructed to eat a diet containing 30 percent protein, 30 percent fat—mostly unsaturted fat, and 40 percent carbohydrates—low glycemic index carbohydrates.

High Fat Diet: No more than 20 grams of carbs for two weeks, 50 grams after that

The high-fat group was instructed to eat no more than 20 grams of carbohydrates per day for the first two weeks, and then increase their carbohydrate intake up to 50 grams per day after two months, and, after that, limit their carbohydrate intake in order to maintain their weight loss.

This is the same advice as the Atkins Diet.

High Carb Diet: 55% carbs, less than 30% fat, 15% protein, and 25-30 grams of fiber

The high-carbohydrate group were instructed to consume at least 55 percent of their calories from carbohydrates, less than 30 percent of their calories from fat—less than 8 percent from saturated fat—, 15 percent of calories from protein, and to try to consume 25-30 grams of dietary fiber each day.

Triglycerides improved the most in the high-protein group: -36% vs -25% vs -16%

In all three groups, there were small improvements in blood pressure, total cholesterol, HDL cholesterol, LDL cholesterol, blood sugar levels, insulin levels and triglyceride levels.

The only reading that stands out after one year as being considerably more improved than any other group was a decrease in the triglyceride levels in the high-protein group.

Triglyceride levels in the high-protein group fell by 36 percent, from 162 mg per deciliter to 103, compared to a decrease of 25 percent in the high-fat group, falling from 166 mg/dL to 125, versus a decrease of 16 percent in the high-carbohydrate group, falling from 167 mg/dL to 140.

 

ZONE DIET BETTER THAN ATKINS DIET IN THE LONG RUN

High-fat group gained more weight after 6 months than the other two groups

The high-protein, Zone-type Diet, seemed to work the better than either the high-fat, Atkins-type Diet or the high-carbohydrate, Ornish-type Diet in the long run for both weight loss and for improvement in risk factors for both cardiovascular disease and diabetes.

“Despite the initial improvements in the [

high-fat, Atkins-type Diet] group, during the final 6 months, this group had an increase in waist circumference and fat mass, which was significantly greater than the increase seen in the [high-carbohydrate, Ornish-type Diet] and [high-protein, Zone-type Diet] groups

,” the researchers noted.

“Triglyceride and 2 [hour] glucose levels also increased [in the high-fat, Atkins-type Diet group],” they continued.

“Although HDL cholesterol at 12 months was higher on [the high-fat, Atkins-type Diet] than an [the high-carbohydrate, Ornish-type Diet], the deterioration of other important metabolic variables associated with diabetes and cardiovascular risk suggests that

a high-fat approach has no overall long-term benefit when compared with the [high-carbohydrate, Ornish-type Diet] conventional approach

,” the concluded.

High-protein group largely maintained their weight loss and improvements in risk factors

The high-protein, Zone-type diet was best for maintaining weight loss in the long run and for maintaining improvements in risk factors.

“In contrast [to the high-fat and high-carb diets], those following

the [high-protein, Zone-type diet] appeared to have a particularly favourable outcome

,” the researchers went on to say.

“

The improvements, which occurred at 6 months, were largely maintained

so that at 12 months weight and fat mass were around [13 pounds and 9 pounds] lower than at baseline [at the beginning of the study].”

“

Furthermore, the [high-protein, Zone-type diet] group had significantly more individuals who had lost a clinically meaningful amount of weight than the [high-carbohydrate, Ornish-type Diet] group.

”

“The initial improvements in waist circumference, fasting triglyceride and insulin were all maintained [in the high-protein, Zone-type diet group].”

They recommend AGAINST high-fat, Atkins diet for long-term use

“There is no evidence for long-term benefit of [high-fat] diets such as the Atkins diet,” the researchers stated.

“While weight loss and associated metabolic improvements occur during the first 6 months, there is rapid regression of many benefits during the following 6 months, to the extent that at 12 months there are few remaining advantages over and above that achieved on the [high-carbohydrate] diet,” they continued.

“These observations and other potential disadvantages of a high-fat diet such as its thrombogenic potential argue strongly against its use in the long term,” they finally conclude.

 

COMMENTS

Zone better in the long run because it is easier to follow

This study changed my mind.

Until today, I believed that there was really no difference between The Zone Diet and The Atkins Diet.

I believed that they both worked because they were high in protein, which spontaneously reduces appetite and calorie intake, and low in carbohydrates, which increases the amount of fat that is burned.

However, this study suggests that The Zone Diet is superior in the long run to The Atkins Diet, mostly because people are more likely to follow it.

People on the Zone Diet also were more successful at maintaining their weight loss for at least a year.

I believe this was simply because it was easier for people to follow for an entire year than the Atkins Diet.

Perhaps Atkins Diet would work better in the long run never eating more than 50 grams of carbs

One of the downfalls of the Atkins Diet may be that it allows people after two months to increase their carbohydrate intake to whatever level they determine is their limit so that they maintain their weight.

Perhaps most people—and I’m sure that I would do the same—try to fool themselves into thinking, “Well, I’ll go ahead and eat these cookies today and then cut back on my carbs tomorrow.”

It just doesn’t work.

REFERENCE

Mcauley K, Smith K, Taylor RW, Mclay R, Williams S, Mann J. Long-term effects of popular dietary approaches on weight loss and features of insulin resistance. Int J Obes (Lond). 2005 Sep 13.

AUTHOR’S CORRESPONDENCE

Professor Jim I. Mann
Department of Medical and Surgical Sciences
Edgar National Centre for Diabetes Research
University of Otago
PO Box 913
Dunedin, New Zealand
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