Weight loss is a matter of eating fewer calories than you use during your daily activities, which means it's possible to lose fat from simply dieting; however, this isn't necessarily the most effective way to lose weight. Those who participate in a combined diet and exercise program are likely to lose more weight and experience greater improvements in body composition than people who use either diet or exercise alone, according to a study published in Obesity in 2012. Speak with your doctor before starting a new diet or exercise program to ensure they're safe for you.
Eating Fewer Calories for Weight Loss
Men typically need between 14 and 18 calories per pound to maintain their weight, depending on their activity level, and women need between 12 and 16 calories per pound. For each pound you'd like to lose, you need to eat 3,500 calories fewer than you burn or increase your activity level to burn this many extra calories -- or a combination of the two. This means to lose weight at a rate of 1 to 2 pounds per week, you need to eat 500 to 1,000 fewer calories each day than your body needs to maintain your current weight. While you may be tempted to keep cutting calories to lose weight at a faster rate, don't go too low. Women need to eat at least 1,200 calories per day and men need at least 1,800 per day to avoid slowing down their metabolisms.
Diet Composition for Losing Fat
Cutting calories isn't the only way to lose weight; it's also important to choose the right types of foods, since they will help make it easier for you to cut calories without feeling too hungry. Concentrate on eating lean protein, vegetables and fruits and reduce the amount of sweets, fatty foods and refined carbohydrates that you consume. Protein is particularly important during weight loss, as it helps increase satiety and limit muscle loss, especially if you get between 25 and 30 grams of protein per meal, according to a review article published in The American Journal of Clinical Nutrition in 2015. Some good protein choices include skinless chicken breast, seafood, legumes, eggs and low-fat dairy products.
It's also important to get the right proportions of fat and carbohydrates in your diet. The University of Colorado, Colorado Springs recommends getting 30 percent of your calories from protein, 25 percent from fat and 45 percent from carbohydrates if you're trying to lose weight. For a 1,200-calorie diet, this means 90 grams of protein, 33 grams of fat and 135 grams of carbohydrates per day. For a 1,800-calorie diet, you'd consume 135 grams of protein, 50 grams of fat and 202 grams of carbohydrates per day.
Cardio to Speed Up Fat Loss
While it's possible to lose weight and fat through diet alone, you'll get better results if you exercise as well. Exercise helps increase the beneficial effects of protein on body composition during weight loss, notes a study published in 2005 in The Journal of Nutrition. The longer or more vigorously you exercise, the more weight you're likely to lose.
For weight-loss purposes, aim for at least 300 minutes each week of moderate-intensity exercise or 150 minutes of vigorous exercise. You're exercising at a moderate intensity if you can still hold a conversation but you can't sing, and, once you can no longer hold a conversation, you're up to a vigorous intensity.
If you're most concerned about losing belly fat, cardio is even more important. Loss of abdominal fat is more likely when you exercise as opposed to just cutting calories, according to a study published in Medicine and Science in Sports and Exercise in 2003.
Improve Results With Resistance Training
Skipping resistance training during weight loss decreases the amount of fat you'll lose. About 1 out of every 4 pounds you lose from dieting without resistance training will come from muscle instead of fat. Participate in at least two strength training sessions per week on nonconsecutive days to ensure your weight lost comes from fat, not muscle; in addition, do a variety of different exercises to target all the major muscle groups in the body, such as the chest, abdominals, back, arms, shoulders and legs.
- University of Colorado Colorado Springs: Your Guide to Nutrition Basics
- American Council on Exercise: Caloric Cost of Physical Activity
- American College of Sports Medicine: Metabolism Is Modifiable With the Right Lifestyle Changes
- Archives of Internal Medicine: Effects of the Amount of Exercise on Body Weight, Body Composition, and Measures of Central Obesity
- Drugs.com: Exercise for Weight Loss: Calories Burned in 1 Hour
- Medicine and Science in Sports and Exercise: Exercise-Induced Weight Loss Preferentially Reduces Abdominal Fat
- Obesity: Effect of Diet and Exercise, Alone or Combined, on Weight and Body Composition in Overweight-to-Obese Post-Menopausal Women
- University of Illinois at Urbana-Champaign: Dieting That Works
- The American Journal of Clinical Nutrition: The Role of Protein in Weight Loss and Maintenance
- The Journal of Nutrition: Dietary Protein and Exercise Have Additive Effects on Body Composition During Weight Loss in Adult Women
- Nutrition, Metabolism & Cardiovascular Diseases: High Protein Diets Decrease Total and Abdominal Fat and Improve CVD Risk Profile in Overweight and Obese Men and Women With Elevated Triacylglycerol
- The Journal of Nutrition: A Reduced Ratio of Dietary Carbohydrate to Protein Improves Body Composition and Blood Lipid Profiles During Weight Loss in Adult Women
- Journal of the American Dietetic Association: Lean Mass Loss Is Associated With Low Protein Intake During Dietary-Induced Weight Loss in Postmenopausal Women