What’s more fattening, candy or chips?

Over a period of 20 years, researchers have accompanied more than 120,000 people on the search for the worst fattening foods.

The ranking holds a surprise.

It does not sound so dramatic: about 380 grams gained the participants of a large U.S. study on average per year. But as time adds up so does the weight – after the 20 years study period participating men and women carried an average of 7.6 kg more weight around with them than at the beginning of the overweight study.

Using data from 98320 men and 22557 women scientists around Dariush Mozaffarian of the Harvard Medical School detected which foods were more strongly associated with weight gain. As described in the ‘New England Journal of Medicine‘ report, the data came from three major studies – the first and second Nurses’ Health Study, in which nurses across the U.S. participated and the ‘Health Professionals Follow-up Study’, which examined men working in health care. At the beginning of the study participants were of normal weight.

Obesity is a worldwide problem, current data suggest that a half billion people are considered overweight, 500 million even as obese because they have a body mass index over 30.

Potatoes turned out to be fattening

The study participants declared their current weight every four years and also explained what foods they had eaten, whether they practiced sport, smoked and how much time they spent watching TV. The researchers then calculated how changed eating and lifestyle habits impact weight gain respectively loss. So they traced, what foods were eaten more or less and in what frequency in a four-year period compared to the prior four years.

On snack, little surprising, proved as particularly devastating for gain weight: potato chips. Any extra serving (30 grams of chips) manifested itself after four years in the form of 770 grams of gained weight. Per serving of potatoes, 580 grams were gained, while French fries (1.5 pounds) had a significantly greater effect than boiled potatoes or mashed potatoes (260 grams). The drinking of sugary soft drinks was associated with 450 grams of weight gain, red meat and sausages accounted for about 430 grams each.

Surprisingly, however, was the result for sweets: the daily serving of dessert or sweets was associated with an increase of about 180 grams only.

Who, on the other hand, ate more vegetables, fruits, whole grains, nuts or yogurt compared to the previous 4-year-period, diminished their weight.  Weight reduction was about 100 grams per serving of vegetables, 220 grams per serving of fruit, 170 grams for whole food products, 260 for nuts and even 370 grams for yogurt, – in which the study did not distinguish between full-and low-fat dairy products.

Eating nuts in addition to chips to reduce weight?

Well, that is obviously not the formula against obesity. ‘These foods contain calories and can not violate any physical laws,’ the scientists write. That the participants lose weight if they eat more vegetables, nuts or yogurt, can only be explained by the fact that they substituted lower quality food and thus received a fewer calories.

The total influence of eating habits on the weight is more than other lifestyle habits, even if every hour in front of the TV was calculated as 140 grams more weight after four years by the research.

The researchers point out that only 50 to 100 kilo calories too many per day could lead to gradual weight gain, as it took place in the study with many participants. To prevent obesity, they recommend to consume some foods, like chips and sugary soft drinks, less and others, such as vegetables, more.

This is consistent with many well-known dietary recommendations.