It’s a fact we’ve heard quite a lot – Americans are fatter than ever. According to the Centers for Disease Control and Prevention, 67 percent of Americans aged 20 and older are overweight.

Now researchers in California say high-calorie, sugar-packed beverages are to blame for our ever-expanding waistlines.

"For the first time, we have strong scientific evidence that soda is one of the – if not the largest – contributors to the obesity epidemic," said Dr Harold Goldstein, executive director of the California Center for Public Health Advocacy.

Researchers from the Center for Public Health Advocacy and the UCLA Center for Health Policy Research interviewed 42,000 Californians of all ages for the study.

They found 24 percent of adults drink one or more non-diet sodas a day. They’re 27 percent more likely to be overweight than those who don’t drink soda.

The results for children were even worse – with 41 percent of kids between the ages of 2 and 11 and 62 percent of adolescents (between 12 and 17 years old) drinking at least one sugar-sweetened drink a day.

Some experts say living a lifestyle that includes a healthy diet with plenty of exercise is the best way to maintain a healthy weight.

For those trying to lose or control their weight, the alkaline diet may be helpful. It is based on citrus fruits, vegetables, tubers, nuts and legumes.