Weight gains among Europeans have been linked to consumption of more American-style fast foods like hamburgers, pizza and sweetened soft drinks, according to a study released on Tuesday.

“High consumption of sugar-sweetened drinks has been associated with weight gain and obesity in the United States,” wrote the authors of the study, published in the American Journal of Clinical Nutrition. “This trend may also be affecting populations with different eating patterns who increasingly are adopting typical U.S. dietary patterns.”

Investigators explored the effects of soft drinks and other fast foods on more than 7,000 middle-aged and well-educated Spanish men and women. Questionnaires on total daily calorie intake, frequency of consumption of multiple food items and alcohol, smoking, physical activity and other lifestyle variables were collected over two years.

Approximately half the group gained weight over the period, the study found. It also showed significant but weaker links between weight gain and consumption of red meat and sweetened fruit juice.

“During follow-up we observed that 49.5 percent of our study population experienced some increase in their body weight,” the study found.

The authors emphasized that fast foods are generally fiber-free and consumers ultimately lose the benefit of a traditional Mediterranean diet to prevent weight gain.

“A wide array of evidence suggests that fiber may exert this beneficial role through several mechanisms, which include effects on satiety, glucose metabolism, energy density and the rates of ingestion and gastric emptying,” the study found.