What is a risk associated with a very low calorie diet (VLCD)?

The key risk associated with a very low calorie diet (VLCD) is indeed an increased risk of malnutrition. VLCDs typically involve drastically reducing caloric intake, often to levels that do not meet the body's nutritional needs. This can lead to insufficient intake of essential vitamins, minerals, and other nutrients needed for overall health, resulting in negative health outcomes.

Malnutrition can manifest in various forms, including deficiencies that affect immune function, bone health, muscle mass, and overall energy levels. Long-term adherence to a VLCD can also lead to metabolic adaptations that further complicate the weight loss process and create a potential cycle of dieting and weight regain.

In contrast, while some may think that a very low calorie diet could facilitate muscle gain due to an initial focus on protein intake, the overall energy deficit and insufficient caloric intake generally do not support muscle maintenance or growth. Furthermore, VLCDs do not inherently lead to reduced calorie needs; in fact, they may cause the body's metabolism to slow down as it adapts to a lower energy intake. Enhanced energy levels are less likely on a VLCD due to the significant energy deficit and potential nutrient deficiencies.