Effects of Different Dietary Models on Eating Behavior and Obesity Management in Overweight and Obese Individuals: A Randomized Controlled Trial

The group that will be applied the Mediterranean diet will be prepared with diet lists that include 35-40% carbohydrate, 15-20% protein and 35-45% fat (\>50% Monounsaturated Fatty Acid (MUFA)) of daily energy. The Mediterranean diet pyramid will be explained to the participants who will be applied the Mediterranean diet, and the portions and frequency of olive oil, nuts, olives, fish, yogurt, fruits and vegetables that they should consume will be planned by the dietitian. The Mediterranean diet pyramid recommends the frequency of foods that should be consumed daily, weekly and monthly. It recommends consuming fish and seafood at least twice a week, 2 portions of white meat, 2-4 portions of eggs, less than 2 portions of red meat, 1 portion or less of processed meat and less than 3 portions of dessert. It is recommended to consume 2 portions of dairy products, 1-2 portions of oil seeds and nuts, more spices, herbs, garlic and onions on a daily basis.

When writing the weight loss diets applied to the individuals in the standard diet group, it will be taken into account that 45-60% of the energy comes from carbohydrates, 10-20% from protein and 20-35% from fat, as specified in the Turkish Nutrition Guide (TUBER). It will be planned that 10% (preferably 7-8%) of the total energy from fat will come from saturated fats (fat found in animal foods, butter, tallow, tail fat), 12-15% from monounsaturated fats (olive oil, hazelnut oil, rapeseed oil) and 7-10% from polyunsaturated fats (corn, soy, sunflower and cottonseed oils containing n-6 fatty acids and fish, fish oil, walnut, flaxseed containing n-3 fatty acids). It will be stated that this ratio is 1 part solid oil, 1 part any vegetable oil and 1.5 or 2 parts olive oil among the oil types.

In time-restricted nutrition, the focus is on when the food is consumed rather than the type of food. However, in medical nutrition treatment of obesity, the content of the meals is also important along with the time (Soran and Öney 2022). As stated in the Turkish Nutrition Guide (TÜBER), it will be taken into account that 45-60% of the energy comes from carbohydrates, 10-20% from protein and 20-35% from fat (Ministry of Health, 2022). A time-restricted nutrition model will be implemented from intermittent fasting diet models. The time restriction will be planned as 8 hours of eating and 16 hours of fasting, suitable for the lifestyle of the individuals. The feeding time for individuals who agree to participate in the study will be determined as 11.00-12.00 and 19.00-20.00. Individuals will be given 2 main meals and the first meal will start with breakfast or lunch according to their wishes.