The Eco-Atkins diet is rich in vegetable proteins from gluten, soy, nuts, fruits, vegetables, cereals and vegetable oils. (Eric Risberg/Associated Press)

Replacing meat-based protein in the Atkins low-carb diet with veggie-based protein may help people to lose weight and lower levels of bad cholesterol, Canadian researchers say.

In a small-sample study in Tuesday's Archives of Internal Medicine, Dr. David Jenkins of St. Michael's Hospital and the University of Toronto reported that an "Eco-Atkins" diet high in plant protein worked better than a high-carb vegetarian diet for reducing levels of low-density lipoprotein or LDL. LDL, also known as "bad" cholesterol, raises the risks of heart attacks and strokes.

In the traditional Atkins diet, people eat fewer carbohydrates and more meat. The diet helps lower blood fats known as triglycerides and raises high-density lipoprotein cholesterol or HDL, the "good" cholesterol, but it also tends to increase LDL cholesterol levels.

"This lack of a benefit for LDL-C control is a major disadvantage in using this dietary strategy in those already at increased risk of coronary heart disease," the study's authors wrote.

In the four-week study, two groups ate about 60 per cent of their estimated calorie needs.

The first group of 22 overweight men and women with high levels of LDL cholesterol ate an Eco-Atkins diet high in vegetable proteins from gluten, soy, nuts, fruits, vegetables, cereals and vegetable oils.

A control group of 22 people ate a high-carb, low-fat diet including low-fat dairy and whole grain products.

People in both groups lost about the same amount of weight: about four kilograms, or 8.8 pounds.

People in the Eco-Atkins group, however, lowered their LDL cholesterol and blood pressures more than those eating a high-carb diet.

Premature to switch

It's not known whether further reducing carb intake would provide more benefits, the authors noted, concluding that a plant-based, low-carbohydrate diet high in vegetable proteins may be an effective option in treating those aiming to lose weight and lower LDL concentrations.

Most high-protein, low-carbohydrate diets advocated by many commercial weight-loss programs have been subjected to little scientific scrutiny, Dr. Katherine Tuttle, M.D., and dietician Joan Milton of the Providence Medical Research Center at Sacred Heart Medical Center and the University of Washington School of Medicine, Spokane, Wash., said in accompanying editorial.

"The article by Jenkins et al provides insight into debatably more effective and possibly safer tactics for designing higher-protein diets for weight loss and cardiovascular risk reduction," they wrote.

"However, it is premature to recommend the 'Eco-Atkins’ diet as a weight-loss diet of choice," without confirming it works in larger studies of more diverse and higher-risk people, the pair added.

This study was supported by Solae, LLC, Loblaw Cos., and the federal government's Canadian Research Chair Program.