By following a healthy diet and exercising regularly, a person can expect to lose approximately 20 to 30 pounds in three months. The amount a person can lose in three months varies based on his starting weight and fitness level.
Reducing calories by 500 per day burns 1 pound per week. For most people, it is safe to lose 1 to 2 pounds per week through diet. Eating healthy foods, such as chicken, fruits, vegetables, fish and egg whites, helps to avoid crash diets. Eating less than 1,200 calories per day can cause muscle loss. For maximum weight loss, a person should perform cardiovascular exercises, such as running, swimming and kickboxing, to burn more calories and increase weight loss. He should include strength-training exercises, such as lifting weights, to build muscle, which burns calories. He should exercise 20 minutes to one hour for five to six days per week.
An average of 3 to 4 pounds per week of weight loss is safe if it is accomplished through a healthy diet and exercise. Sugar and starches cause fluid retention. Cutting back on both can shed up to 5 pounds of water weight. Weight loss slows down as a person gets smaller, because his body requires fewer calories. Those seeking to lose weight should consult a doctor before beginning a new diet or exercise program.