You’ve probably heard about the importance of “calories in vs calories out” if you’ve ever tried to lose weight.
This approach is predicated on the assumption that you will lose weight if you consume fewer calories than you burn.
Some argue that the sort of food you consume is far more critical than the number of calories it contains, both in terms of weight loss and long-term health.
This article aims to determine if the “calories in vs. calories out” paradigm is functional.
What’s the ‘calories in, calories out model?
The “calories in vs. calories out” paradigm assumes that to maintain a constant weight, the number of calories consumed must equal the number of calories expended.
“Calories in” refers to the calories obtained from the meals consumed, while “calories out” refers to the number of calories expended.
Three major physiological processes cause calorie expenditure:
- The fundamental metabolism. Most of the calories you consume are used by your body to maintain basic activities such as your heartbeat. This is also known as your basal metabolic rate (BMR) (1).
- Digestion. Around 10-15% of your calories are used to power digestion. This is referred to as the thermic effect of food (TEF), and it changes depending on the foods consumed (2, 3).
- Physical exercise. The extra calories from your diet fuel your physical activity, such as exercises and everyday duties like walking, reading, and dishwashing.
Your weight will remain consistent if the number of calories you consume from food equals the number of calories you burn to maintain your metabolism, digestion, and physical activity.
As a result, the “calories in vs. calories out” paradigm is correct. To lose weight, you must create a calorie deficit.
Weight loss requires a calorie deficit
To lose weight biologically, you must consume fewer calories than you burn. There is no getting around that.
Once your body’s energy requirements are fulfilled, surplus calories are stored for later use — some in your muscles as glycogen, but the majority as fat. Thus, consuming more calories than you expend will result in weight growth, and eating fewer calories than required would result in weight loss (4).
Some research shows that what you eat is more important than how much you eat, meaning that the calorie level of your diet is unimportant for weight loss. These investigations, however, are founded on a few faulty assumptions (5, 6, 7, 8).
Those who argue that low-carb diets help people lose weight despite consuming the same (or even more) calories frequently depend on diet journals to estimate calorie consumption.
Diet notebooks are typically incorrect, even when completed by nutrition specialists (9, 10, 11).
Furthermore, some studies merely report total weight loss without noting whether the weight loss was due to muscle, fat, or water loss.
Different diets influence muscle and water losses differently, giving the impression that they are more successful in fat loss when this is not the case (12).
Controlling for these variables, studies consistently indicate that weight loss is always the consequence of a calorie shortfall. This is true whether your calories come from carbohydrates, fat, or protein (13, 14, 15, 16, 17).
Health is more than just ‘calories in vs. calories out.’
While the “calories in vs. calories out” concept is essential for weight loss, not all calories are created equal regarding health.
This is because, regardless of calorie level, different meals have varied impacts on various processes in your body.
The source of calories impacts your hormones and health differently.
Different meals might have varying effects on your hormone levels.
An excellent example is a difference in the effects of glucose and fructose. Although these two simple sugars have the same number of calories per gram, your body metabolizes them differently (18).
A diet high in added fructose is associated with insulin resistance, elevated blood sugar levels, and higher triglyceride and LDL (harmful) cholesterol levels than a diet high in glucose (19).
Fruit, on the other hand, includes natural fructose, fiber, and water and does not have the same detrimental consequences.
Furthermore, the fat in your diet can have various consequences on your reproductive hormone levels. For example, diets high in polyunsaturated fats increase fertility in healthy women (20).
Furthermore, substituting saturated fats in your diet with unsaturated fats may reduce your risk of heart disease even if both types give the same number of calories per gram (21).
The types of food you eat affect how full you feel.
Your nutritional intake influences your appetite and fullness levels.
For example, a 100-calorie portion of beans can satisfy your appetite considerably more efficiently than a 100-calorie piece of sugar.
This is because diets high in protein or fiber are more satisfying than those poor in these nutrients (22, 23, 24).
The candy, lacking in fiber and protein, is far more likely to cause you to overeat later in the day, lowering the chances that your “calories in” will equal your “calories out.”
Similarly, fructose raises levels of the hunger hormone ghrelin more than glucose.
It also does not excite your brain’s fullness regions like glucose, so you will not feel as complete after consuming fructose as you would after eating glucose (25, 26).
This is why most processed meals high in fructose but low in protein or fiber make it more challenging to maintain an energy balance.
The source of calories has different effects on your metabolism.
Different foods have different effects on your metabolism. Some, for example, need more effort to digest, absorb, or metabolize than others. The thermic impact of food is the metric employed to quantify this study (TEF).
The greater the TEF, the more energy is required to digest a nutrient. TEF is highest in protein and lowest in fat. This suggests that a high-protein diet necessitates higher calorie expenditure than a low-protein one (2, 3).
This is why consuming protein is typically claimed to stimulate your metabolism more than carbohydrates or fat. However, regarding weight loss, the TEF of meals appears to have a minor impact on your calorie balance (27, 28, 29).
Why nutrient density matters
The number of nutrients in a diet per calorie varies substantially.
Nutrient-dense foods include more vitamins, minerals, and beneficial substances per gram than less nutrient-dense meals.
Fruits, for example, have many more nutrients than doughnuts. The fruit has far more vitamins, minerals, and valuable plant components than vegetables.
Vegetables, whole grains, legumes, meat, fish, poultry, dairy products, and unsalted nuts and seeds are some examples of nutrient-dense diets.
On the other hand, processed foods such as white spaghetti, soda, cookies, chips, ice cream, and alcohol are said to have a poor nutritional density.
Nutrient-dense diets have regularly been linked to a decreased risk of chronic illnesses such as diabetes and heart disease and may even help you live longer (30, 31).
The “calories in vs. calories out” approach ignores nutritional density, which is a solid reason to question its relevance to your health.
The bottom line
The “calories in vs. calories out” concept is essential for weight loss from a biological standpoint.
Regardless of your food, you will only lose weight if you consume fewer calories than you burn.
However, this approach fails to account for nutritional density, which is extremely important to your health. Furthermore, various meals can affect your hormones, metabolism, appetite, and feelings of fullness, influencing your calorie consumption.
Certain meals can help you maintain a healthy weight and improve your overall health. Concentrating simply on calories may cause you to overlook the overall picture.
0 Comments