Not all calories are equal – Unpacking the Science of Calories: Why Different Foods Affect Your Body in Different Ways?
A calorie is a unit of energy that measures the amount of heat required to raise the temperature of one kilogram of water by one degree Celsius. However, when it comes to maintaining a healthy body and managing your weight, not all calories are equal.
Numerous studies have shown that certain diets - like high-protein, low-carb or a combination of both - can lead to greater weight loss than other diets that contain varying levels of fats, proteins, and carbohydrates.
If all calories were the same, then you would expect similar results from individuals who consume the same number of calories regardless of the type of food. However, this is not the case. Dietitians and nutrition experts understand that several factors influence how the body processes and utilizes calories.
To help you navigate the world of calories and nutrition, here are some key insights that you should keep in mind.
Unpacking Metabolizable Energy: What It Is and How It Affects Your Body?
Back in the late 1800s, chemist W.O. Atwater and his team developed a system to determine the amount of energy, or calories, that different foods contain. They accomplished this by burning up samples of various foods and measuring the amount of energy they released in the form of heat.
However, not all of the energy in food that can be burned up in a laboratory is actually available to the human body. Scientists refer to the energy that can be utilized by the body as metabolizable energy, which is the difference between the total energy in food consumed and the energy that is excreted from the body in urine and feces. Atwater came up with a percentage of the calories that each of the three macronutrients - protein, carbohydrates, and fats - contain that would actually be metabolizable.
Understanding the concept of metabolizable energy is crucial for making informed dietary choices. It's not just about the total number of calories that a food contains, but also about how many of those calories are actually usable by the body. By taking metabolizable energy into account, you can better tailor your diet to meet your specific needs and achieve your health goals.
So the next time you're considering what to eat, remember that not all calories are created equal. Knowing how many of those calories are metabolizable can help you make more informed and effective dietary choices.
How much energy do we need?
Your body's energy expenditure - that is, the amount of energy it takes to keep you alive and moving - is affected by what you eat. This includes the energy you use to breathe, digest food, keep your blood flowing, and move your body - all of which contribute to your metabolism.
The quality of your diet can impact your body's energy expenditure, also known as the thermic effect of food. For instance, in one study, people who ate the same amount of calories per day but followed either a low-carbohydrate or a low-fat diet showed differences in total energy expenditure of about 300 calories per day. Those who followed a very low-carb diet used the most energy, while those who followed a low-fat diet used the least.
In another study, high-fat diets led to lower total energy expenditure than high-carb diets did. Meanwhile, increasing protein intake to 30-35% of a person's diet can boost their energy expenditure. While substituting carbohydrates for fat doesn't alter energy expenditure, consuming protein causes an 11%-14% increase above the resting metabolic rate. Protein is harder for the body to break down, which is why it has a higher thermic effect.
Overall, diets high in carbohydrates, fat, or both lead to a 4%-8% increase in energy expenditure, while meals high in protein cause a higher increase above the resting metabolic rate. Protein is harder for the body to break down, so it requires more energy to digest.
By understanding how your diet can impact your body's energy expenditure, you can make more informed dietary choices that support your health goals. Keep in mind that while different diets may impact energy expenditure differently, it's still important to maintain a healthy overall diet to promote overall well-being.
Quality of calories
The quality of the calories you eat can affect your blood sugar levels, energy metabolism, and weight gain. Dietitians often consider a food’s glycemic index and glycemic load to determine how quickly and how much it will increase your blood glucose levels. Foods high on the glycemic index/load, such as white rice, cakes, cookies, and chips, can cause a rise in blood glucose, leading to insulin release and storage of excess energy as fat. On the other hand, foods low on the glycemic index/load, such as green vegetables, raw peppers, mushrooms, and legumes, may help regulate blood sugar levels.
Fiber content is another important factor to consider. Foods high in fiber, such as fruits, vegetables, whole grains, and beans, tend to have less metabolizable energy and can help you feel full on fewer calories. This is because your body can’t digest fiber for energy.
Empty calories from foods with minimal or no nutritional value, such as white sugar, soft drinks, and ultra-processed snacks, are also a concern. These foods don’t provide much, if any, benefit in the form of protein, vitamins, or minerals, and can have a negative effect on health. On the other hand, nutrient-dense foods that are high in nutrients or fiber, such as spinach, apples, and beans, can provide health benefits while being relatively low in calories.
Lastly, certain foods are associated with weight gain or weight loss. Foods that contribute most to weight gain include potato chips, potatoes, sugar-sweetened beverages, and processed and unprocessed meats. Conversely, vegetables, whole grains, fruits, nuts, and yogurt are inversely associated with weight gain.
Quality over Quantity of Calories
Weight loss is commonly associated with calorie intake and exercise output. However, health and longevity involve more than just losing weight. While weight can influence health, a healthy weight alone does not guarantee overall well-being.
Plant-based diets are associated with longevity, and in areas where people live the longest, diets consist primarily of plant-based foods with low to no animal-based protein and moderate amounts of mono- and polyunsaturated fats.
Many people assume that carbohydrates are the root cause of weight gain, but it's not that simple. Carbohydrates can be found in soda and candy, but also in fruits and vegetables. Reducing intake of simple carbs like baked goods and sugary drinks can improve health, but eliminating complex carbs like fruits and vegetables has the opposite effect.
Research indicates that a plant-based diet with protein and carbohydrates from vegetables, fruit, nuts, and legumes is the healthiest diet for preventing chronic diseases like heart disease, cancer, and hypertension.
Calorie quality matters more than the number of calories consumed, and not all calories are created equal. Different foods affect fullness, insulin response, fat storage, and metabolic energy expenditure differently. Therefore, the quality of calories consumed is crucial to maintaining a healthy lifestyle.
Impact of food on hormones
It's not just the number of calories that matter, but also the impact of the macronutrients on your hormones.
Insulin is a common example of a hormone affected by food. Sugar and high-glycemic-index carbs can cause a greater insulin response compared to protein and fiber-containing carbs. Fat has the least immediate insulin action, but may have a mild longer-term effect, especially when overeaten.
Studies suggest that high insulin levels can lead to obesity and metabolic dysfunction. Lifestyle therapies that reduce insulin levels may help with weight loss. Therefore, foods that minimize insulin secretion may be better suited for weight loss in some individuals.
Certain foods may trigger the release of satiety hormones such as leptin, CCK, PYY, and GLP-1 while inhibiting ghrelin (a "hunger" hormone). Protein-containing foods trigger satiety hormones more than other foods, and fibrous carbs trigger them more than refined carbs.
Therefore, the type of calories we consume affects our hormones and satiety differently, not just the number of calories.
About me
And short story about LEET DIET
As a choreographer and aerial gymnast, I had always been interested in maintaining a healthy lifestyle. Diets had been my hobby, but I never truly enjoyed them until I discovered the Keto diet. After reading numerous books about how our bodies work and the benefits of a high-fat, low-carb diet, I decided to give it a try. I never looked back. The Keto lifestyle quickly became my passion, and I began experimenting with new recipes and meal plans. That's when I decided to share my knowledge with the world and created Leet Diet, a website filled with delicious Keto-friendly recipes and helpful tips for anyone looking to adopt a healthy lifestyle.
