Energy balance

A 12-week very low-calorie ketogenic diet (800-1000 kcal/day, 70% fat, 20% protein, 10% carbs) significantly reduces body weight and body fat percentage in overweight/obese adults, but also significantly decreases resting metabolic rate (RMR) and total energy expenditure.

A 12-week very low-calorie ketogenic diet (800-1000 calories, high fat) leads to significant fat loss in obese individuals, but it also significantly slows down your resting metabolism. This metabolic slowdown is a normal adaptive response to severe calorie restriction and should be expected. Long-term maintenance requires careful refeeding strategies to mitigate metabolic adaptation.