The outcome of this review reinforces the work Public Health England is doing to tackle child obesity and will inform the European dietary guidelines that myself and the team at the University of Newcastle, Australia, are preparing with colleagues from the European Association for the Study of Obesity and European Federation of Dieticians.

The findings indicated that participation in moderate to high intensity interventions could result in short-term and longer-term changes in total dietary intake and proportions of fat, protein and carbohydrate. However, severe nutrient restrictions, such as a very low carbohydrate intake, were not sustained.

“Food-based guidance, tailored for individuals and families, delivered by qualified dietitians, appears to be more effective in achieving longer-term dietary changes, rather than the provision of general dietary advice only,” Professor Collins said.

Six months post-intervention, there was in general, a reduction in energy intake of about 800kj per day, which is equivalent to one to two servings of discretionary choices - or junk food. At the 12-month mark, the daily energy intake was still 500kj lower.

An example of a healthy lunchbox for children - showing a sandwich, cheese and crackers, salad and fruit

An example of a healthy, balanced lunchbox

“Even if energy intake does not continue to decrease, small changes are enough to lower body weight over time,” Professor Collins said.

“It comes down to swapping something like a muesli bar for an apple, soft drink for water. The small changes add up.

“The message for families – what you put in the lunchbox or give for afternoon tea really matters.”

Professor Collins said health organisations and policy makers, including the World Health Organisation, would find the data valuable to inform the development of evidence-based dietary guidelines for childhood obesity management.

The study was partially funded through the Hunter Medical Research Institute (HMRI) and The Rainbow Foundation.

The paper, Impact of weight management nutrition interventions on dietary outcomes in children and adolescents with overweight or obesity: A systematic review with meta-analysis, was published in the Journal of Human Nutrition and Dietetics in February 2021.