WHAT’S NEW?

IS ONE WEIGHT LOSS DIET MORE EFFECTIVE THAN OTHERS? 

If you’re trying to lose weight, there’s no shortage of ‘diets’ and weight loss programs promising impressive results. But is there really one type of diet that is more effective than others?

A new study published in the April edition of the British Medical Journal (BMJ) set out to answer this question. The researchers conducted a systematic review and meta-analysis looking at the effect of different dietary macronutrient patterns and popular diet programs on weight loss and improvement of cardiovascular risk factors in overweight adults. They included 121 randomised controlled trials involving almost 22 000 subjects. The diets included low fat, low carbohydrate and popular named diets such as Atkins, Zone, DASH (Dietary Approaches for Stopping Hypertension) and Ornish.

When they compared these diets to usual or control diets, low fat (such as Ornish), low carbohydrate (such as Atkins and Zone) and moderate macronutrient diets (such as DASH and Mediterranean) all resulted in moderate weight loss at 6 months but not 12 months. The average weight loss at 12 months was 2kgs and any differences between the diets are described as being trivial to small.

At six months, each of these diets also reduced blood pressure and the low fat and moderate macronutrient diets reduced levels of ‘bad’ LDL cholesterol. However, these improvements almost disappeared by 12 months.

The authors conclude that people wanting to make dietary changes to lose weight should choose the diet they prefer. This is an important point. For example, an older study comparing four different diets with different macronutrient ratios (Atkins, Ornish, Zone and Weight Watchers) found that weight loss was similar on all four diets and what predicted success was cutting kilojoules and being able to stick to the diet.

This new study, and previous research comparing different diets for weight loss, show us that there are different ways to achieve the same result – it’s not one size fits all. The key is to find an eating plan you can adopt for the long-term as this is the only way to lose weight and keep it off.

Read more:

• Comparison of dietary macronutrient patterns of 14 popular named dietary programmes for weight and cardiovascular risk factor reduction in adults: systematic review and network meta-analysis of randomised trials. 
• Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial. 

   
Kate Marsh is an is an Advanced Accredited Practising Dietitian, Credentialled Diabetes Educator and health and medical writer with a particular interest in plant-based eating and the dietary management of diabetes and polycystic ovary syndrome (PCOS).    
Contact: Via her website www.drkatemarsh.com.au.