Research has shown that most people eat approximately the same weight of food on a daily basis, with very small day-to-day variations. Studies have shown that people eat about 3 to 5 pounds of food per day, regardless of whether it contains foods with a low, medium, or high calorie density.  Therefore, if you strategically eat green light foods with a low calorie density, by the time you're full you will have eaten substantially fewer total calories than if you ate foods in the yellow or red light categories (higher calorie density). 

Simply stated, if your digestive system accepts the same weight of food per day, then filling it with foods low on the calorie density scale will maximize your ability to lose weight and gain insulin sensitivity simultaneously. If instead you're trying to maintain your current body weight or gain weight, eat the majority of your diet from the most calorie-dense foods in the green light category, including sweet fruits, starchy vegetables, legumes, and intact whole grains. 

This research shows that you can cut out as many as 2,000 calories per day by eating foods low in calorie density, and you're likely to feel just as satisfied as if you were eating foods with a high calorie density. How is this possible? It's simple--as long as you eat approximately the same weight of food per day, your digestive system won't know the difference between a diet with a low-calorie density and one with a high calorie density, but eating fiber-rich high-quality plant-based foods will make a tremendous difference in your metabolic health.