Eat 5,000 calories a day consistently, and you're bound to gain weight. If you're like most people, even if you have a high metabolism or do significant levels of physical activity, 5,000 calories is a calorie surplus, which means you take in more calories than you burn.
How much weight gain to expect from following a 5,000-calorie diet depends on your age, size, activity level and gender, as well as how long you're maintaining a calorie surplus. A one-day binge is unlikely to make a tremendous difference in your weight, but consistently eating 5,000 calories for weeks could lead to a notable increase in body fat.
5,000 Calories a Day
The average person burns between 1,600 and 3,200 calories per day. Smaller, older women who are inactive burn on the lower end of this range, while young, larger men who are quite active burn on the higher end.
According to the Mayo Clinic, 1 pound of fat equals 3,500 calories. If you burn just 1,600 calories per day, a 5,000-calorie, one-day binge represents a 3,400-calorie surplus, so you might gain almost a pound as a result. However, if your burn rate is closer to 3,200, the surplus is 1,800 calories, which could result in a weight increase of 1/2 pound. Keep in mind that some people may burn more than 3,200 calories per day depending on their metabolism, so your experience might be slightly different.
Healthy Weight Gain Rates
Unless your doctor has directed you to gain weight quickly due to health concerns, a more moderate calorie surplus of just 250 to 500 calories per day is recommended to help you gain a slow, healthy 1/2 to 1 pound per week. Gaining at a faster rate means you're likely adding extra body fat to your frame, since you can only realistically put on about 1/2 pound of muscle per week.
When you gain weight, you want to add muscle and not just fat weight; muscle is a healthier body tissue than fat. It improves your strength, daily function and appearance. An excess of fat can endanger your health. To gain muscle, you'll need to stick to a resistance training program to go along with your slight calorie surplus.
Healthy Diet for Weight Gain
Consuming a diet of 5,000 calories daily is challenging; it requires large quantities at each meal and multiple high-calorie snacks per day. You might find it easier to take in 5,000 calories daily if you resort to unhealthy foods full of sugar and saturated fat.
Some chain restaurant meals or desserts come in at 2,400 or more calories, but usually this is from inflated serving sizes or large amounts of unhealthy ingredients. Eating junk food to gain weight isn't a good idea though; even if you're underweight, you can still develop chronic conditions, such as Type 2 diabetes or heart disease, associated with overeating these types of foods.
Weight gain is best achieved through a balanced diet plan that increases your calorie intake through a mix of proteins, dairy, starchy vegetables, whole grains, fruits and unsaturated fats. Instead of resorting to junk food, eat larger portions of healthy foods, such as sweet potatoes, lean steak or poultry, brown rice and milk. Other ways to get more calories include adding milk to soups and cereal; stirring dried milk powder or cheese into casseroles; spreading peanut butter on fruit and toast; snacking on nuts and dried fruit; and topping salads and sandwiches with avocado.
Consistency for Weight Gain
A one-day binge that topped 5,000 calories might make you feel sluggish and overweight the next day, but it's unlikely to do much permanent damage as long as you go back to eating a healthy, portion-controlled diet and exercising regularly the next day.
If your goal is to gain weight, it'll take several weeks of a moderate calorie surplus and resistance training to gain healthy muscle. This slow and steady pace is preferable over a fast gain that puts on fat. If you embark on a year of strength training with a calorie surplus, expect, at most, an average muscle gain of about 0.4 pounds per week — or about 20 pounds total.