You may not lose weight healthily if your deficit makes consuming proper nutrients impossible. The body can adjust its usage of calories way down in the event

You may not lose weight healthily if your deficit makes consuming proper nutrients impossible. The body can adjust its usage of calories way down in the event of a perceived famine, making the amount of calories consumed no longer contain a deficit. The RMR can change during a diet as both fat and muscle require maintenance, and you nearly always lose both during a period of deficit. This can make maintaining a significant deficit very difficult Finally, there is evidence that people who have lost significant weight have a reduced metabolic weight (and hunger for more calories) even five years after they completed their dieting. This may explain why the failure rate of people >100 lbs overweight losing and maintaining is nearly 95%