Eating as much as you want and never gaining weight may sound like a dream come true -- but for most people, it is just a dream. What you eat and how much you eat are closely tied with how much you weigh, and overdoing it at meals and snacks will eventually result in gradual weight gain.
You gain weight when you eat more calories than you burn. However, the "calories burned" aspect of that equation relies on several factors, including age, height, weight, sex, activity level, genetics and even the foods you eat -- for example, protein burns more calories during digestion than fat. As a result, you'll have some trial and error figuring out how much you can eat without gaining. For example, it’s possible for a very small, very active teenager to eat 4,000 calories daily and still not gain weight, but a sedentary post-menopausal woman might limit herself to 1,500 calories daily and still be gaining. No matter what, though, you probably can't eat as much as you want -- whatever you burn daily is your calorie limit, and exceeding it means you'll gain weight.
Active Metabolic Rate
When you exercise regularly or work at a physically demanding job, your metabolic rate increases, and you can eat more without gaining weight. However, it's usually easier to eat less than it is to burn off extra calories with a workout. One-half cup of vanilla ice cream, for example, has about 140 calories. But if you weigh around 125 pounds, it would take you half an hour of moderate-intensity calisthenics to burn those calories off. So even though exercise means you can eat a little more without gaining weight, you can't eat a lot more without gaining.
Obviously, eating fast food and doughnuts at every meal is more likely to make you gain weight than eating salads. But you can still pack on pounds with salads and other low-calorie foods. According to Brooke Schantz, registered dietitian with the Loyola University Health System, it’s possible to overdo it and gain weight on almost any type of food, even fruits and vegetables. But because they’re lower in calories and higher in water and fiber, naturally low-energy-dense foods like fruits and vegetables are more conducive to weight loss or weight maintenance than weight gain.
Amount of Food
Of course, whether you gain weight from a free will eating plan also depends on how much you want to eat. If you don’t enjoy feeling stuffed, you may choose to eat small meals and “light” foods, which definitely make it possible to eat all you want and still maintain or even lose weight. As registered dietitian Lorraine Matthews-Antosiewicz points out, eating until you are satisfied is distinctly different from eating until you are full. If you are a compulsive eater or tend to practice mindless eating, however, you’re likely to put on weight faster as a result of those habits.
- Loyola University: Is There Such a Thing as Eating Too Many Fruits and Vegetables?
- McKinley Health Center: Breaking Down Your Metabolism
- NJ Nutritionist: Eat Until You Are Satisfied, Not Full
- USDA National Nutrient Database: Ice Creams, Vanilla
- Harvard School of Public Health: Calories Burned in 30 Minutes for People of Three Different Weights