**5. Dietay management of obesity**

Recommendations for weight management emphasize the importance of healthy eating patterns which include consumption of nutrient-dense foods, limiting portion size of energy-dense foods, and reduce overall energy density. A unifying factor for weight loss across dietary patterns is energy density, when a diet's energy density is reduced; individuals consume satisfying amounts of food for fewer calories. The goal of dietary therapy is to reduce the total number of calories consumed.

The optimal diet for prevention of weight gain, obesity, metabolic syndrome, and type 2 diabetes is fat-reduced, fiber-rich and high in low-energy density carbohydrates (fruit, vegetables, and whole grain products). The Mediterranean eating pattern that emphasizes intake of low-energy dense fruits, vegetables, legumes, seafood, and dairy foods has proved effective in the management of obesity. However, higher amounts of fat (30–40% of total energy), especially from olive oil, are recommended with the Mediterranean diet. Even with this level of healthy fats, the Mediterranean diet recommends high proportion of fruit and vegetable which can help to keep the overall diet relatively low in energy density.

It has been established that different types of carbohydrate have varying effects on metabolism and health. Some carbohydrates are healthier than others; those with lower glycemic indexes (or GI) have a slower and flatter blood glucose response. They take longer to digest and can help us feel full thus preventing overeating and weight gain. Lower GI foods are less refined (or processed) such as whole grains, legumes, fruit, and vegetable. High GI foods are refined carbohydrate and contribute to weight gain.

Many high-carbohydrate foods common to Western diets produce a high glycemic response, promoting postprandial carbohydrate oxidation at the expense of fat oxidation, thus altering fuel partitioning in a way that may be conducive to body fat gain [31].
