Over the past three decades, the rising obesity epidemic has been accompanied by a proliferation of weight-loss plans.
However, as a new study by researchers from the University of Massachusetts Medical School (UMMS) reveals, these weight-loss plans vary significantly in their ability to positively affect heart health.
In A Dietary Quality Comparison of Popular Weight-Loss Plans published in the October issue of the Journal of the American Dietetic Association, several weight-loss plans significantly outperformed others in their ability to reduce the risk of cardiovascular disease.
Diets which came out tops
Specifically, the investigators found that the Ornish, Weight Watchers High Carbohydrate and New Glucose Revolution plans scored highest when measured by the Alternate Healthy Eating Index (AHEI).
Proven to be a strong predictor of cardiovascular disease, the AHEI is a measure that isolates dietary components that are most strongly linked to cardiovascular disease risk reduction.
“Obviously, obesity is associated with an increased risk for cardiovascular disease,” said UMMS Assistant Professor of Medicine Yunsheng Ma, PhD, MPH, one of the study’s primary authors.
“Optimal weight-loss plans should facilitate both weight loss and chronic disease prevention, specifically cardiovascular risk reduction.”
Which diets were evaluated
Choosing weight-loss plans based on their status on The New York Times bestseller list during the past five years, Dr Ma and colleagues evaluated the dietary quality of the New Glucose Revolution, Weight Watchers High Carbohydrate and Weight Watchers High Protein, Atkins 100- and 45-gram Carbohydrate, South Beach Phase 2 and Phase 3, The Zone, Ornish and the 2005 US Department of Agriculture (USDA) Food Guide Pyramid plans.
Weight Watchers and the 2005 USDA Food Guide Pyramid plan were included because they are the largest commercial weight loss plan and the current government recommendation, respectively.
Elements used to determine dietary quality included ratio of white to red meat, ratio of polyunsaturated fat to saturated fat, and quantities of fruit, vegetables, nuts, legumes, cereal fibre and trans fats, all of which are known to affect cardiovascular health.
Of a maximum 70 points, the AHEI scores from highest to lowest were: Ornish (64.6); Weight Watchers High Carbohydrate (57.4); New Glucose Revolution (57.2); South Beach/Phase 2 (50.7); Zone (49.8); 2005 USDA Food Guide Pyramid (48.7); Weight Watchers High Protein (47.3); Atkins/100 g Carb (46); South Beach/Phase 3 (45.6) and Atkins/45g Carb (42.3).
Fruit and veggie diets are best
According to study co-author and UMass Memorial Medical Centre registered dietitian Barbara Olendzki, RD, MPH, an instructor in medicine at UMMS, “The highest performing plans - Ornish, Weight Watchers High Carb and the New Glucose Revolution - fared well due to an emphasis on fruits and vegetables, higher whole grain composition and lower trans fats.”
“One of the unexpected findings is that the 2005 USDA Food Guide Pyramid, the current government recommendation, fared significantly worse than the New Glucose Revolution, Weight Watchers High Carbohydrate and Ornish plans,” said Ma.
“The USDA dietary guidelines were originally devised to prevent nutrient deficiencies and it's clear that we need to modify or rebuild the pyramid to look into cardiovascular disease prevention, as it is the leading cause of death and disability for Americans. Americans deserve a better dietary guideline and recommendation”.
“Patients can lose weight with most dietary plans in the short term, but whether the plan they choose maximizes cardiovascular risk reduction over the long term should also be a consideration for patients and health care providers,” concluded study co-author Sherry Pagoto, PhD, UMMS assistant professor of medicine and a clinical psychologist at the UMass Memorial Weight Centre. –(EurekAlert)