SWAPPING out starchy carbohydrates for whole grains, fruits and vegetables slashes how much weight you put on in midlife, a study shows.
Ditching foods like potatoes and white bread for healthy ones like berries and brown bread helped cut the risk of piling on the pounds, US researchers found.
Eating 100g more per day of non-starchy veg like broccoli, carrots and spinach reduced how much people put on by 3kg every four years.
For comparison, eating 100g more of starchy products like bread, rice and pasta increased their weight by 1.5kg over the same period.
Dr Yi Wan, of Harvard University, said: “The findings highlight the potential importance of carbohydrate quality and source for long term weight management, especially for people with excessive body weight.
“Limiting added sugar, sugar sweetened beverages, refined grains, and starchy vegetables in favour of whole grains, fruit, and vegetables may support efforts to control weight.”
Putting on weight in midlife is common, as hormonal changes reduce how much muscle mass you have and metabolisms begin to slow.
This is particularly the case for women, with the menopause often causing a build-up of fat around the belly, hips and thighs.
Previous research has shown carrying a spare tyre is more dangerous than being generally overweight.
Around 38 per cent of adults in England are overweight, and a further 26 per cent obese.
The NHS says obesity costs £6.1billion a year, but the total cost of all linked conditions is believed to be much higher.
The latest study, published in the BMJ, looked at how what you eat affects your risk of putting on weight in middle age.
They tracked more than 136,000 men and women for 24 years, measuring their weight and asking about their diets every four years.
On average, people put on 1.5kg on each check up, amounting to 8.8kg in total.
Eating 100mg added sugars a day saw them put on 0.9kg more every four years.
Just 10mg more per day of fibre saw them put 0.8kg less weight on during the same time frame.