simplifies dieting and gives people hope that they can lose weight if they simply stick to a caloric deficit, which is true. On the other hand, it overly simplifies nutrition and people may still eat unhealthily (albeit less) and as soon as they are done with their CICO diet yoyo and gain the weight back because they haven't taken into account many other factors that are important in nutrition that affect body composition, metabolism, and ultimately long-term weight loss.