In 2009, a 4-week clinical trial putting overweight people on a low-carbohydrate vegan diet, known as the Eco-Atkins, was released. I mentioned it in my article Of Oil and Ethics.
It was promising because after 2 weeks, LDL cholesterol levels went from 174 to 134 mg/dl. After 4 weeks, LDL cholesterol levels appeared to be stuck, at an average of 136 mg/dl. Participants also lost weight and had some other improvements, and they reported feeling more satisfied than did the participants in the control diet (a lacto-ovo, semi-low-fat vegetarian diet).
It took the researchers awhile to publish it, but they just released a report on what happened to the participants after 6 months (1). Unfortunately…not much. Their LDL cholesterol levels were back up to 157 mg/dl at the end of 6 months. They had still lost some body weight (15 lbs) and their risk for heart disease had improved over baseline.
The analysis was done on an intention-to-treat basis which means that people who didn’t stick with the diet were included in the final results (or their numbers were estimated). Overall diet compliance was fairly low at only about 34% of the recommended foods.
For those on Eco-Atkins, percentage of fat went up from their normal diet, but only from 34.4 to 36.0% of calories. And when you consider that their calories went down, from 1,840 to 1,388, their total fat intake actually went down, from 70 to 56 g.
The authors suggested that increases in monounsaturated fat (MUFA) could account for some of the improvements in heart disease risk factors, but their MUFA fat intake, while increasing slightly on a percentage basis, actually went down in total, from 27 to 23 g.
When you add in the fact that fiber increased from 12 to 21 g, it seems that all of the improvements could simply be attributed to a lower intake of calories and an increase in fiber.
Still, the Eco-Atkins did better than the 28% fat, lacto-ovo vegetarian diet. However, at baseline, the participants in the lacto-ovo group had an average daily caloric intake of 1,598, which was 242 calories less than the Eco-Atkins dieters. During the study, the lacto-ovo vegetarian dieters ate a very similar amount of calories to the Eco-Atkins dieters (1,347 and 1,388 respectively). As such, the Eco-Atkins dieters had a lot more room for improvement which could possibly explain why they did somewhat better.
In conclusion, this trial provides evidence that fiber is good and calories are bad for lowering cholesterol and losing weight.
1. Jenkins DJ, Wong JM, Kendall CW, Esfahani A, Ng VW, Leong TC, Faulkner DA, Vidgen E, Paul G, Mukherjea R, Krul ES, Singer W. Effect of a 6-month vegan low-carbohydrate (‘Eco-Atkins’) diet on cardiovascular risk factors and body weight in hyperlipidaemic adults: a randomised controlled trial. BMJ Open. 2014 Feb 5;4(2):e003505. | link