When it comes to diet programmes, brand names don’t make much difference, according to a new review.
Low-carb or low-fat diets resulted in the most weight loss, but despite a difference of a few pounds between groups, all the programs in the study were about equally effective, says lead author Bradley C Johnston.
“The weight loss differences between branded diet programmes were small with likely little importance to those seeking to lose weight,” he says.
Johnston, of the Hospital for Sick Children Research Institute in Toronto and McMaster University in Hamilton, Ontario, says any diet programme should include exercise and behavioural support.
The analysis included 49 randomised controlled trials that tested 11 popular branded diets for at least three months. All of the participants were overweight or obese, and they all had daily nutrient or calorie targets. Some had exercise goals as well.
The low-carb diets, like Atkins, South Beach and Zone, require that no more than 40% of daily calories come from carbohydrates and another 30% come from protein.
The low-fat diets, including the Ornish and Rosemary Conley diets, specify that less than 20% of calories come from fat, and 60% come from carbohydrates.
Johnston and his team also included trials of moderate macronutrient diets, like Biggest Loser, Jenny Craig, Volumetrics, Nutrisystem and Weight Watchers, which also require around 60% of calories from carbohydrates but allow more from fat and less from protein than the low-fat diets studied.
Compared to no diet at all, each of the diets produced more weight loss, but low-fat and low-carb were most successful, according to results in the Journal of the American Medical Association (JAMA).
At the six-month point, people on low-carb diets had lost an average of 8.6kgs, which dropped to 7.3kgs at one year. Low-fat dieters lost an average of more than 7.7kgs by six months, which also dropped to 7.3kgs by one year. Moderate macronutrient dieters lost an average of 5.7kgs after one year.
The different diet brands within each category didn’t make much difference, the authors write. For example, among the low-carb diets, the Atkins diet resulted in about two more kilograms of weight loss than the Zone diet at the six-month point.
“I think in general when people follow a specific plan and have a support system and guidelines that pull them away from their normal everyday behaviour, I would expect to see weight loss,” says Lindsay Malone, a registered dietician at the Cleveland Clinic who was not part of the new review.
While weight loss appeared slightly greater with low-carb versus low-fat diets, “with either one you’re making a lot of significant changes, eliminating junk food and junk calories,” Malone says.
She and her colleagues typically don’t endorse specific diet brands. Instead, they sit down with patients and talk about their lifestyle, what has worked for them in the past, and recommend certain characteristics of diets individually, she says.
Though the moderate macronutrient diets in the review resulted in slightly less weight loss than others, they may still be the best choice for some people, she says.
“Moderate macronutrient provides the greatest variety so is easiest for some people,” says Malone. “If they are feeding a family or eating on the go a lot, maybe that is a little more doable for them.”
Though the brands themselves didn’t differ meaningfully, there are still advantages to branded diet programmes, Johnston says.
“Branded diets are likely more effective than general dietary guidelines because they typically involve a comprehensive programme including behavioural support and physical activity,” he says. “Some also include prepared foods, recipes and meal ideas.”
Health professionals can help assess which diet programme the patient is most likely to stick to and achieve lasting weight loss, as well as a diet’s potential impact on other health measures like cholesterol and blood pressure, says Johnston.
“We know that you can achieve weight loss with more than one type of diet,” Malone says. “The diet that really should be presented or offered to people is the one they’re going to stick to.” – Reuters
Food for thought
Eating sensibly is key to getting the nutrients your body needs and maintaining your weight. Take a look at the video below for some great pointers.