What is the Yo-Yo Effect and How to Avoid It?

The yo-yo effect is a phenomenon that occurs after a weight loss period and involves alternating weight loss and weight gain. It is assumed that this effect occurs when a person who has lost weight starts to regain weight within 5 months after completing the diet. In this period, weight fluctuations can exceed 10% of the body weight. Initially, gaining extra pounds can be minimal, but over time, one can regain all the lost kilograms or even gain more. It is assumed that maintaining a stable weight without regaining it requires about 5 years after completing the diet, as in this period new eating habits can be established.

One of the causes behind the manifestation of the jo-jo effect is a disturbance in the production of leptin. Leptin is a protein generated by fat cells. It plays a crucial role in food consumption regulation. Its adequate level in the body is responsible for the sensation of satiety. During weight loss, the quantity of fat diminishes, causing a decrease in leptin production. As a result, after concluding a reduction diet, there is a high probability of an increase in appetite and feeling of hunger.

Fat-free body mass is the human body weight (bones and active tissues) without fat tissue. It describes the level of nutrition of the body. Fat tissue has significantly more energy (about 7700 kcal/kg) than fat-free body mass (1000-1200 kcal/kg). An improperly planned weight loss leads to the body initially reducing the fat-free body mass, whose loss is not desirable. Why? Let's take the example of a person who weighs 100 kg, who has 45 kg of fat tissue and 55 kg of fat-free body mass, with low physical activity during the day. The value for the basal metabolic rate (BMR) = 370 + 21.6 x BMC (fat-free body mass) = 1558 kcal. Additionally, low physical activity must be taken into account, which results in 1558 x 1.6 = 2492.8 kcal. Let's assume that the person lost 40 kg (20 kg of fat tissue and 20 kg of fat-free body mass) during the weight loss. Of course, it may seem that the person has achieved great success, but considering the significant reduction in fat-free body mass, their BMR will be significantly reduced. This is where the yo-yo phenomenon begins. After a successful diet, the person returns to their old eating habits, consuming the same amount of calories as before starting the diet, but is not aware that this can lead to a significant weight gain. As a result, they return to their old weight and even gain a few extra kilograms. With the reduction of fat-free body mass, the BMR also decreases.

In order for the weight loss process to proceed correctly, it is necessary to: - follow a diet with a sufficiently defined energy and calorie surplus. - remember not to reduce the number of calories consumed below the minimum metabolism, as their deficiency can lead to serious health consequences; - avoid detox diets and fasting periods that require a drastically low amount of calories; - introduce regular physical activity and strength training, which at a positive calorie surplus will help maintain the majority of muscle mass, preventing a decrease in the basic metabolism; - provide an adequate amount of protein in the diet, at least 1,5 g/kg, in order to preserve the largest possible amount of muscle mass. Additionally, protein helps to achieve a feeling of satiety; - maintain healthy eating habits after the weight loss diet.

The process of fat reduction can be lengthy and sometimes arduous. Without cautious actions, it may result in the opposite of the intended outcome. The majority of individuals who attempted to follow an extremely deficient diet with a negative calorie balance have likely experienced the yo-yo effect. To maintain the reduced weight, it is crucial to adhere to a diet with a proper calorie balance and adequate protein intake. Additionally, it is beneficial to engage in regular physical activity, which aids in preserving the maximum amount of muscle mass.