Just to add on to what you are saying > The Reference Daily Intake (RDI) used in nutrition labeling on food and dietary supplement products in the U.S. and Can

Just to add on to what you are saying > The Reference Daily Intake (RDI) used in nutrition labeling on food and dietary supplement products in the U.S. and Canada is the daily intake level of a nutrient that is considered to be sufficient to meet the requirements of 97–98% of healthy individuals in every demographic in the United States. Due to individual variations you may need less. So falling short of the RDI isn't necessarily a problem. Edit: Consider what the RDI for calories would be. If it meets the requirements for 97% of people, then it must be a quantity sufficient for some people with very high metabolism. So eating RDI-calories would likely make a significant amount of people obese.