A diet is calorie-sufficient if:
- It includes enough calories to support a physically active lifestyle based on height, weight and body composition.
- Weight, strength and energy levels are able to be maintained or increased over time.
- net calories are greater than or equal to zero.
While calorie insufficiency predictably results in weight loss, weight loss from undereating (including hygienic water fasting) does not tend to be sustainable long term unless
healthy lifestyle choices, rather than restrictions, become a normal and consistent practice afterwards.