Eating food can increase your metabolism for a few hours.
This is called the thermic effect of food (TEF). It's caused by the extra calories required to digest, absorb and process the nutrients in your meal.
Protein causes the largest rise in TEF. It increases your metabolic rate by 15–30%, compared to 5–10% for carbs and 0–3% for fats (1).
Eating protein has also been shown to help you feel more full and prevent you from overeating (2, 3, 4, 5, 6, 7, 8).
One small study found that people were likely to eat around 441 fewer calories per day when protein made up 30% of their diet (9).
Eating more protein can also reduce the drop in metabolism often associated with losing fat. This is because it reduces muscle loss, which is a common side effect of dieting (10, 11, 12, 13, 14, 15).
People who drink water instead of sugary drinks are more successful at losing weight and keeping it off (16, 17, 18, 19, 20).
This is because sugary drinks contain calories, so replacing them with water automatically reduces your calorie intake.
However, drinking water may also temporarily speed up your metabolism (18, 21).
Studies have shown that drinking 17 ounces (0.5 liters) of water increases resting metabolism by 10–30% for about an hour (22, 23).
This calorie-burning effect may be even greater if you drink cold water, as your body uses energy to heat it up to body temperature (21, 24).
Water can also help fill you up. Studies show that drinking water a half an hour before you eat can help you eat less (25, 26, 27).
One study of overweight adults found that those who drank half a liter of water before their meals lost 44% more weight than those who didn't (19).
High-intensity interval training (HIIT) involves quick and very intense bursts of activity.
It can help you burn more fat by increasing your metabolic rate, even after your workout has finished (28, 29, 30, 31).
This effect is believed to be greater for HIIT than for other types of exercise. What's more, HIIT has also been shown to help you burn fat (32, 33, 34).
One study in overweight young men found that 12 weeks of high-intensity exercise reduced fat mass by 4.4 pounds (2 kg) and belly fat by 17% (35).
Muscle is more metabolically active than fat, and building muscle can help increase your metabolism (36, 37, 38, 39).
This means you will burn more calories each day, even at rest (40).
Lifting weights will also help you retain muscle and combat the drop in metabolism that can occur during weight loss (41, 42, 43, 44).
In one study, 48 overweight women were placed on a diet of 800 calories per day, along with either no exercise, aerobic exercise or resistance training (45).
After the diet, the women who did the resistance training maintained their muscle mass, metabolism and strength. The others lost weight, but also lost muscle mass and experienced a decrease in metabolism (45).
Highly interactive yet the bottom line is, "Get off your ass".
