Low-carbohydrate weight-loss diets increase the production of ketones formed form the incomplete breakdown of fats. Ketogenic diets cause rapid short-term weight loss but are no more effective than other low-calorie diets for long term weight loss or weight maintenance. A university study published in Endocrinology, used rats and concluded that ketogenic diets have long-lasting negative effects on blood sugar regulation. Rats that were fed low-carbohydrate diets then switched to a normal diet showed impaired insulin sensitivity and poor blood sugar control. Yo-yo dieting (bouncing between ketogenic and normal diets) may have long-term negative effects on blood sugar regulation.