A widely debated question in nutrition is: Are all calories made the same? Is a calorie just a calorie?
Intuitively, you would think there is no way a calorie of steak or broccoli could be the same as a calorie of Skittles. There has to be a stark difference between a calorie of a nutrient-dense whole food and a calorie of a highly processed “food” product.
But when it comes to weight loss and weight gain, some people argue that it is all about “calorie in, calorie out.”
The truth? It's a combination of factors. When talking about nutrition, there is always a bit of nuance.
Calories are a unit of energy that influences weight gain or loss, but hormones also play a significant role in hunger and eating behavior. A calorie of broccoli equals a calorie of Skittles, in energy terms. The differences arise in how these calories influence your body.
Your body processes energy from consumed calories in one of two ways — energy is either used immediately or stored for later. Overeating results in excess energy storage (weight gain), while inadequate consumption forces your body to tap into energy reserves (weight loss).
In those simplest terms, “calorie in, calorie out” is at the foundation of weight loss and weight gain.
Yet, not all calories impact your body the same way. Food choices make a significant difference, and ignoring that fact is why so many people become frustrated and never see results.
These essential nutrients are metabolism boosters and appetite suppressants. Foods rich in protein and fiber, like lean meats, lentils, veggies, and berries, reduce hunger by impacting hormones that manage cravings. This doesn’t mean calories don’t matter, but it does mean you are less likely to overeat if you make the right food choices.
So, while calories-in versus calories-out determines weight gain or loss, food choices significantly impact appetite and metabolism. It isn’t just about food quantity or food quality — it’s about both.