London - It has taken Harvard’s finest minds, 24 years of study and 130,000 volunteers to discover what may seem blindingly obvious to the rest of us – spuds make you fat.
Researchers spent decades painstakingly logging the volunteers’ eating habits to create a comprehensive list of fruit and vegetables that make you put on weight – and those that will help you lose it.
The US scientists confirmed that potatoes are one of the most fattening vegetables. But more surprisingly, perhaps, sweetcorn came top of the list followed by peas, with spuds taking third place.
Celery, which is often thought of as the dieter’s friend, only has a modest effect on weight loss, while blueberries, prunes and cauliflower are a much better option for slimmers. The findings come from a Harvard School of Public Health analysis of detailed dietary information provided by American men and women.
Every four years for up to 24 years, they answered questions about how often they ate 131 foods. They were also weighed regularly and provided information about smoking, exercise, TV viewing habits and other aspects of their lifestyles. Not surprisingly, those who increased their intake of fruit and vegetables generally lost weight.
Fruit was twice as good for this as veg, with every extra portion a day leading to around half a pound (about 230g) of flab being shed over four years. Blueberries were the best for slimming, with an extra handful a day linked to almost a pound and a half (around 680g) of weight loss. Prunes, apples, pears, strawberries, raisins and grapes, also scored high on the weight-loss scale.
Reasons for this range from people substituting them for fattening desserts to them being particularly rich in plant compounds called polyphenols, chemicals that alter the human metabolism and the way the body processes sugar.
Cauliflower came top among vegetables, followed by green beans, broccoli and Brussels sprouts. Writing in the journal PLOS Medicine, researcher Monica Bertoia said that while the amount of weight gained or lost over four years may seem small, the figures would soon add up.
She added: ‘Combining an increase of one to two servings of vegetables and one to two servings of fruits daily would be associated with substantial weight change.’
Rebecca Lawton, of the British Dietetic Association, said that rather than filling up on potatoes, weight-conscious people should try brown rice or wholemeal bread.
But she said there was a still a place for spuds on our plates, adding: ‘There are lots of good things about potatoes. They are high in vitamin C, potassium and fibre – and quite filling.’
However, their high starch and low water content means they are higher in calories than most vegetables. Only baked, boiled and mashed potatoes were included, so the finding cannot be explained by eating too many chips.
Daily Mail