But substituting fish for red meat, high-fiber foods for processed pastries and eating more vegetables may push more fattening foods off your plate, and at the least, prevent weight gain.

It is said that some will get fat if they don't have breakfast, because the diet is not balanced, the body takes in more than what they need.

While most studies on diet focus on changes needed to help obese people lose weight, the study by the Harvard team showed tiny changes in diet and lifestyle can make a big impact.