What Causes Obesity – Excess Calories or Excess Carbohydrates? » Science for Fitness One of the the biggest (if not THE biggest) points of contention in the health and fitness industries is whether excess calories or excess carbohydrates are responsible for high levels of obesity in the United States. Calories In/Calories Out proponents: Those in this camp say a calorie is a calorie and that thermodynamics is the driver. That is, if you eat more calories than you expend, you’re…