In a BMJ study of more than 100,000 men and women, researchers discovered that subclasses of powerful antioxidants called flavonoids – namely flavonols, flavan-3-ols, anthocyanins, and flavonoid polymers – found in select fruits and vegetables may prevent weight gain. The fruits with the greatest effect on weight maintenance were chock full of flavonoids called anthocyanins, and blueberries top this list.
About one-quarter cup of blueberries contains 10 milligrams of anthocyanins, and each 10 mg increase is linked with a 0.1kg less weight gain over four years, the BMJ study found. This may seem insignificant, but it can add up with time, the study authors point out. Exactly how flavonoids deter weight gain is not fully understood but eating foods rich in flavonoids – namely produce – may allow us to feel full sooner, and avoid other less-healthy foods that may lead to weight gain.
“I am a blueberry fan for many reasons,” says Dr Keri Peterson. Antioxidant power aside, blueberries are also rich in fibre which keeps us feeling full longer, she says. “They are among the healthiest fruits to eat.” Berries happen to be among the most-filling fruits. Aim for a cup of blueberries a day as part of an overall healthful diet that is rich in lean protein, complex carbohydrates, healthy fats like olive oil, fruits, and vegetables, she says.
Who cares if an apple a day can keep the doctor away if it also helps keep you trim? Apples are rich in flavonoid polymers and are also packed with fibre, making them one of the best fruits for weight loss when part of a healthy diet. One medium-sized apple is considered one serving. Eat them with the skin on (i.e. unpeeled) to get more fibre, antioxidants, and better control over your blood sugar, says Dr Sharad Paul. Preventing blood sugar spikes and valleys will help banish food cravings and eating binges, not to mention help protect against diabetes.
Pears may also prevent weight gain, according to the aforementioned study, and this is largely due to flavonoid polymers: every extra 138 mg of flavonoid polymers resulted in less weight gain over the four-year study period. “Fruits that are rich in flavonoid antioxidants and high in fibre are great choices,” Dr Peterson says. “Fibre fills you up and creates satiety, so pears and apples give you a lot of bang for your buck.” Make sure to eat the skin too for maximum benefits, adds Dr Paul.
Strawberries help maintain weight for the same reason as their blueberry counterparts: they are rich in anthocyanins. Incorporate one cup of strawberries a day into your diet – try them with breakfast over low-fat yoghurt or steel-cut oatmeal, as a mid-afternoon snack, or as a dessert after dinner, Peterson says. “The concern has been that eating sweet fruits may cause weight gain due to fructose content, however, certain fruits like green apples, pears and berries like raspberries, strawberries and blueberries are among the best fruits to eat as part of a weight management plan not only because they are less sweet, but due to their high flavonoid content.”
First, yes: capsicums are in fact a fruit. Ranking up there with the healthiest fruits, they can also help put the brakes on weight gain when eaten daily, according to the research. In fact, capsicums may even encourage weight loss: capsaicin, the component that gives chilli peppers that kick, seems to encourage white fat cells to convert into energy-burning brown fat, in one study done on rats.
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