It is what many a potato-lover has long suspected: spuds are bad for the waistline.
The humble potato is one of the most fattening vegetables, a study found.
The Harvard researchers said that rather than filling up on potatoes, weight-conscious folk should try brown rice or whole meal bread instead.
Other vegetables that slimmers might want to give a wide-berth include sweetcorn and peas.
Even celery, which is often thought of as the dieter's friend, doesn't magic excess weight away.
However, eating more blueberries, prunes and cauliflower could help slimmers reach their target weight.
The fascinating findings come from a Harvard School of Public Health analysis of detailed dietary information provided by more than 130,000 American men and women.
Every four years, for up to 24 years, they answered questions about how often they ate 131 different foods – including fruit and vegetables.
They were also weighed regularly and provided information about smoking, exercise, TV watching and other aspects of their lifestyle.
The wealth of information generated has been used by researchers for many different purposes but this study focused on fruit and vegetable intake and weight change.
Not surprisingly, upping intake led to weight loss over time.
Fruit was twice as good as veg, with every extra portion a day leading to around half a pound of flab being shed over four years.
Blueberries were the number one fat burner, with an extra handful a day linked to almost a pound and a half 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.
These are credited with a host of health benefits, including altering the metabolism and the body's processing of sugar.
Cauliflower came out top in the vegetable category.
Other veg deemed good for weight loss included broccoli and Brussels sprouts.
Writing in the journal PLoS Medicine, researcher Monica Bertoia said that while the figures for each food may seem small, they would soon add up.
在PLoS Medicine雜志上撰文的研究人員莫妮卡·波托亞（ Monica Bertoia）表示，雖然每種食物產生的數字都不大，但它們很快就會疊加。
She said: 'Although the magnitude of weight change associated with each increased daily serving was modest, 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.'
Even staying at the same weight, rather than gradually getting fatter, is good for health.
However, not all greens are good for the waistline.
Sweetcorn, peas and potatoes were actually linked to weight gain.
And only baked, boiled and mashed potatoes were included, so the finding cannot be explained by people feasting on fatty chips.
Dr Bertoia said that brown rice and whole meal bread are both good alternatives to potatoes.
All of the calculations took into accountother changes to diet, as well as changes to smoking, exercise and sleep that occurred over the years.