Supersize Dilemma

North Americans are becoming more obese because our food portions are getting heftier-at fast food and other restaurants, and at home. Researchers at University of North Carolina at Chapel Hill analyzed national US data of 63,380 people aged two and older. They found that between 1977 and 1996, portion sizes of unhealthy foods such as salty snacks, desserts, soft drinks, fruit drinks, French fries, hamburgers and cheeseburgers, grew markedly. Mexican food grew the largest by portion, increasing an average 1.7 ounces, or 133 calories, followed by hamburgers (1.3 oz/97 calories) and French fries (0.5 oz/68 calories). Recent findings from the university also show that all age groups eat more restaurant food-including fast food-than a generation ago.

When combined with less physical activity than in decades past, greater energy consumption significantly raises the risk of heart disease, stroke, hypertension, diabetes and other health threats, says the study's co-author, Dr. Barry M. Popkin.