What Nutritionists Want You to Know About Calories

The body needs each macronutrient — carbohydrates, fats, and protein — for optimal health. “The most important thing is to eat the best quality,” Jacobson said. For example, a can of soda is full of carbs in the form of simple (and usually processed) sugar. “That’s not good.” An orange — not orange juice — is also high in carbs, but you will also get fiber, vitamins, and minerals, she noted. “So, you can eat two foods with comparable carbohydrate counts, but the benefit is different,” she added.

“[Zero-calorie drinks] are the worst,” Jacobson said. Diet soda is linked to a possible host of issues, including increased calorie intake overall, dementia, kidney problems, and type 2 diabetes. It can also disrupt your gut bacteria, she noted. Some research has shown that artificial sweeteners may induce sugar cravings, alter metabolism, and lead to obesity. This is why diet soda could be killing you in at least 10 ways.

There are 3,500 calories in a pound of fat. Theoretically, if you were to create a daily calorie deficit of 500 calories a day — whether from cutting calories or from exercising or both — that would equate to a pound over the course of a week. “But it’s not usually that simple because the human body is very complex,” Gorin said. Speed of weight loss depends on factors such as metabolism, how much lean muscle you have, how much water weight you’re carrying, and more.

“Gaining muscle is a fantastic way to enable your body to burn more calories,” Gorin said. Increasing muscle tissue can be great for weight loss because muscle burns more calories than fat. This is especially important as you get older because you lose muscle as you age — about 10% each decade after age 45, according to Gorin.

Different drinks range widely on how nutritious they are, Gorin noted. “What you want to keep at a minimum are beverages like sugar-sweetened soda, sugary energy drinks, and coffee drinks with lots of sweeteners.” There are some ways to make these healthier. For instance, you could blend up a frozen mochaccino as a breakfast smoothie, which tastes similar to a Starbucks Frappuccino but doesn’t contain any added sugar at all, Gorin added.