It is no secret that regular exercise and quality sleep have a very positive effect on metabolism in the human body. However, there are many foods that speed up the metabolic process and promote weight loss. Jalapeno, habanero, cayenne and other types of hot peppers directly speed up metabolism and stimulate blood circulation. Hot peppers owe this effect to capsaicin, a compound that is part of them. According to studies, consumption of hot peppers can increase the metabolic rate by 25%. Whole grains are full of nutrients and complex carbohydrates that boost metabolism by stabilizing insulin levels. Slow carbs like oatmeal, brown rice, and quinoa provide longer-lasting energy without the bursts of sugar-rich foods. We need to keep insulin levels low, as insulin spikes tell the body to store extra fat. Rich in calcium, broccoli is also extremely high in vitamins A, K and C. One serving of broccoli will provide you with the necessary amount of folic acid, dietary fiber, as well as various antioxidants. Broccoli is one of the best detox foods you can add to your diet. It is now a known fact that green tea speeds up metabolism. In addition, it is very tasty and rich in antioxidants that are active against free radicals. A study presented by the University of Rio de Janeiro found positive results in weight loss among women who consumed three small apples or pears daily.