Effects of Plant-based Diets on Body Weight and Selected Metabolic Parameters in Obese Patients: a Randomised Controlled Trial of Five Different Diets

Obesity is not only one of the most serious health problems in the world, it is also associated with an increased risk of many other diseases. Despite many preventive measures, the number of people suffering from obesity is constantly increasing, also in Poland. One of the integral elements of treatment is a change in lifestyle, including a change in eating habits. In this context, new dietary models are constantly being considered and eagerly adopted by patients. These are not always rational and evidence-based choices. What's more, what we eat is not only important for our health, but also for the planet. Recently, high-fat diets with a significant carbon footprint have gained popularity.

It is therefore worth considering more plant-based dietary models in the treatment of obesity and its associated disorders. Such a change can simultaneously help reduce greenhouse gas emissions and improve environmental quality, as well as benefit our health - both directly and indirectly.

There is a growing body of scientific evidence suggesting that limiting meat consumption may be beneficial to health, leading to weight loss, improvements in selected cardiovascular risk parameters and inflammation. However, many questions remain.

For this reason, more plant-based dietary patterns are worth considering in the treatment of obesity and its accompanying disorders. There is growing scientific evidence that limiting meat consumption promotes good health. It has been shown that the implementation of a vegetarian diet can result in weight loss, as well as help in maintaining optimal weight levels more effectively in the long term. This is extremely important for people suffering from obesity. Adherence to meat-restricted diets is also associated with other health benefits, which include an improved lipid profile and other cardiovascular risk parameters, as well as beneficial effects on inflammation and oxidative stress parameters.

Currently, there are only a few intervention studies available that have investigated the effectiveness of plant-based diets in a population of obese adults who previously have not restricted their meat consumption. Most of the studies concern vegetarians, whose awareness of taking care of their diet and lifestyle is, after all, much higher. To some extent, this may explain such optimistic conclusions from observational studies. It is not the only issue associated with research focused on plant-based diets. In experimental studies, the results of dietary interventions are very often compared with no intervention whatsoever. It would therefore be interesting to verify the effectiveness of a vegan or vegetarian diet against current dietary recommendations or another health-promoting dietary pattern - the Mediterranean diet. After all, vegan or vegetarian diets are elimination diets. Should they be recommended for the treatment of obesity and disorders associated with it? Do body weight, cholesterol and glucose levels decrease faster? What risks do they entail and are they difficult to implement? The investigators only know the answers to some of these questions.