‘Calories in, calories out’ is all that matters when it comes to weight loss

The most key element of weight loss is creating a calorie deficit by using more energy than you eat, but it's not the only thing that matters. Even on a very low-calorie diet, there are several factors that may prevent someone from losing weight, and relying simply on calorie intake ignores these factors.

For example, genetics, metabolic adaptations, health disorders like hypothyroidism, hormonal imbalances, and the use of certain medications are some of the reasons that may make weight reduction more difficult for some people, even when they follow a strict diet. Those who adhere to the "calories in, calories out" philosophy frequently focus only on a food's calorie count and ignore its nutritional benefits. Because of this, people may choose low-calorie, nutrient-poor foods like rice cakes and egg whites over high-calorie, nutrient-dense foods like avocados and whole eggs, which isn't the ideal choice for their overall health.