In a perfect world, you could grab a pizza on the way home from your workout, follow it up with a scoop of ice cream, and still lose weight. But in the real world, that is not likely to happen.Weight loss is largely a matter of calories out versus calories in, and not being careful with your diet will lead to a calorie surplus and weight gain.
You can't eat whatever you want and still lose weight, even if you exercise.
Calories In vs. Calories Out
There's a lot of controversy about the concept that weight loss is purely a matter of taking in fewer calories than you burn. Just eat fewer calories than you burn each day and the pounds will drop off, right? Wrong. There are so many other factors at play in weight management, including your genetics, age, sex, health status and more. Even socioeconomics plays a role in weight loss.
That said, controlling your calorie intake is necessary for weight loss and that is only achieved through striking the right balance between the calories you consume and the calories you expend each day through physiological function such as digestion, daily activities of living and exercise activities. Generally, creating a caloric deficit, in which you regularly consume fewer calories than you eat each day, will help you lose weight.
Theoretically, you could create such a deficit by only dieting or only exercising, but it would be very difficult to maintain. That's why the combination of diet and exercise is so important because then cutting calories doesn't just depend on one variable. If you happen to miss a workout or two, you can adjust your calorie intake to make up for it and stay on track.
Food Choices Matter
It's much easier to eat 1,000 calories worth of pizza than it is to eat 1,000 calories of broccoli. That's because ounce for ounce, pizza is way higher in calories. Really, just check out these stats from the United States Department of Agriculture:
Yes, pizza has 10 times the calories of broccoli.
So, let's say you go to the gym and use the elliptical machine for 30 minutes at a moderate pace and then lift weights for 30 minutes. According to Harvard Health Publishing, the average 155-pound person would burn about 450 calories — not too shabby if you're going to go home and eat a 3-ounce baked chicken breast, 1/2 cup of brown rice and a cup of steamed mixed vegetables topped with an ounce of cheddar cheese — a meal that would provide 522 calories.
However, if you are going to eat two slices of pizza, a heaping serving of Caesar salad and a bowl of ice cream, your meal is going to amount to 900 calories or more. If you have a glass of wine or a soda with that meal, you're taking in upwards of 1,000 calories — more than double what you just burned at the gym. See now how eating whatever you want is going to backfire?
All Food Is Not Equal
A calorie is a calorie, right? Think again. One hundred calories from broccoli — about 14 ounces — is going to have a much greater effect on satiety and appetite than 100 calories from pizza — which amounts to an ounce of crust, cheese and toppings. If you eat 14 ounces of broccoli, chances are you're going to feel pretty full, but if you eat only a measly ounce of pizza, you're going to be left wanting more. Unless you have extremely good willpower, you are not going to be able to eat an ounce of pizza and call it quits.
The nutrients in your food make a difference in whether you can lose or gain weight. Foods like pizza and French fries are high in fat, the most caloric of the three macronutrients with 9 calories per gram — more than double the amount of calories in a gram of either protein or carbohydrate, according to the USDA. They're also low in dietary fiber, a noncaloric type of carbohydrate found in plant foods and a crucial component of satiety and appetite control.
Protein also plays a critical role in appetite control. Because both protein and fiber are digested slowly, they suppress the release of a hormone called ghrelin that stimulates hunger. According to a January 2019 review article in the Journal of Nutrition and Metabolism, gastric distension after a meal delays the release of ghrelin, and the longer the duration of the gastric distension, the longer the hormone is suppressed. The rate at which foods are digested determines the duration of gastric distension.
On the flip side, foods that are simple in structure and quickly digested promote little satiety and will result in a quick return of ghrelin and hunger, which leads to increased calorie intake. These foods include sweets, baked goods, white pasta and bread, pizza dough and sugary cereals. Eating these foods instead of complex carbohydrates from whole grains and vegetables and high-quality sources of lean protein will make it hard for you to control your calorie intake for weight loss, no matter how much you exercise.
Effects on Your Health
Weight loss isn't the only thing that should concern you. Eating a lot of junk food, or even overeating foods that are good for you in small amounts, can have deleterious effects on your health. Eating too much sugar not only leads to obesity, but it also causes diabetes and contributes to the development of some types of cancer.
Drinking soda and other sugar-sweetened beverages can increase the amount of visceral fat you have, according to a cross-sectional analysis published in the Journal of Nutrition in August 2014. Visceral fat is the type that sits deep within your abdominal cavity surrounding your organs. Too much of this type of fat has been linked to heart disease, type 2 diabetes and some types of cancer. According to the analysis, regular consumers of sugar-sweetened beverages had a 10 percent higher volume of visceral fat than nonconsumers.
Excess saturated fat in fried foods and processed meats is another concern not to be taken lightly. Eating too much saturated fat leads to increased cholesterol and a higher risk of stroke and heart disease. And then there's the risk of not getting the nutrients you need for good health if your diet is primarily composed of junk foods.
Lastly, if you plan to exercise a lot, you're going to need sustained energy, of which junk foods are a poor source. Complex carbohydrates, lean protein and healthy fats will provide lasting energy, and they'll also provide raw materials for protein building and for recovery so you can get back in the gym and reach your goals ASAP.
- NIH: "Factors Affecting Weight & Health"
- USDA: "Basic Report: 11741, Broccoli, Stalks, Raw"
- Surgical Endoscopy: "Low Socioeconomic Status Is Associated With Lower Weight-Loss Outcomes 10-Years After Roux-En-Y Gastric Bypass"
- USDA: "Basic Report: 21272, Pizza Hut 12" Cheese Pizza, Pan Crust"
- Harvard Health Publishing: "Calories Burned in 30 Minutes for People of Three Different Weights"
- USDA: "Basic Report: 20037, Rice, Brown, Long-Grain, Cooked (Includes Foods for USDA's Food Distribution Program)"
- USDA: "Basic Report: 05064, Chicken, Broilers or Fryers, Breast, Meat Only, Cooked, Roasted"
- USDA: "Basic Report: 11584, Vegetables, Mixed, Frozen, Cooked, Boiled, Drained, Without Salt"
- USDA: "Basic Report: 01270, Cheese, Cheddar, Sharp, Sliced"
- USDA: "Full Report (All Nutrients): 45275926, Family Cesar Salad, UPC: 046567507408"
- USDA: "Full Report (All Nutrients): 45214671, Premium Ice Cream, UPC: 070640011001"
- USDA: "How Many Calories Are in One Gram of Fat, Carbohydrate, or Protein?"
- MedlinePlus: "Soluble vs. Insoluble Fiber"
- Merck Manual: "Carbohydrates, Proteins, and Fats"
- Journal of Nutrition and Metabolism: "The Role of Fiber in Energy Balance"
- Harvard Health Publishing: "There’s No Sugar-Coating It: All Calories Are Not Created Equal"
- Journal of Nutrition: "Sugar-Sweetened Beverage Consumption Is Associated With Abdominal Fat Partitioning in Healthy Adults"
- MedlinePlus: "Facts About Saturated Fats"
- Harvard Health Publishing: "Carbohydrates — Good or Bad for You"