Most popular weight loss diets can lead to modest reductions in both weight and cardiovascular risk factors such as hypertension, a study has found.
Low carbohydrate diets like Atkins and Zone, macro diets like Mediterranean and DASH, and low fat diets such as the Ornish diet, all support weight reduction to some extent.
Researchers suggest that most weight loss diets will have some short-term weight loss effects up to six months so people should choose what diet suits them most and not to worry that other diets might be better.
The weight loss effect of popular named diets appears to diminish at the 12-month point.
Except for the Mediterranean diet in lowering ‘bad’ LDL cholesterol, the cardiovascular health effects will lessen at 12 months for all popular named diets.
Since 1975, obesity has tripled globally, consequently pushing society to promote any dietary program that can improve heart health or grab any weight loss plan.
Hence the study compares different diets to see their impact on weight loss and cardiovascular risk factors including cholesterol levels and high blood pressure.
The team analysed data from 121 trials with nearly 22,000 overweight or obese adult participants who either followed a usual diet or one of 14 popular diets including Atkins, Portfolio, DASH, Mediterranean, Ornish, Biggest Loser, Weight Watchers, Jenny Craig, Zone, Paleolithic, Slimming World, Rosemary Conley, South Beach, and Volumetrics.
In comparison to a usual diet, low fat and low carbohydrate diets showed a reduction of 4 to 5 kg in weight and a modest drop in blood pressure over six months.
The weight loss and blood pressure lowering effect was slightly less for the macro diets group.
People in the Zone, Atkins and DASH group lost between 3.5 and 5.5 kg, suggesting these diets had the largest weight loss effect and greatest impact on lowering blood pressure.
The LDL cholesterol reduction was at the highest for the Mediterranean diet, while dietary advice, Ornish, Biggest Loser, DASH, and a low fat diet were no better than a usual diet in lowering ‘bad’ cholesterol.
The authors wrote:
“The extensive range of popular diets analysed, provides a plethora of choice but no clear winner.”
They advise that we need to focus on how to maintain weight loss instead of discussing what dietary pattern is best.
Unfortunately, most people take no notice of national dietary guidelines that encourage the public to drink less alcohol and soft drinks, reduce salt and sugar intakes, and eat more whole grains, vegetables, and legumes.
The authors concluded:
“If we are to change the weight trajectory of whole populations, we may learn more from understanding how commercial diet companies engage and retain their customers, and translate that knowledge into more effective health promotion campaigns.”
About the author
Mina Dean is a Nutritionist and Food Scientist. She holds a BSc in Human Nutrition and an MSc in Food Science.
The study was published in the BMJ (Ge et al., 2020).