Losing weight essentially boils down to a calorie deficit – burning more calories than you consume, although there are supplements that can help speed things up. To understand how to best achieve sustainable weight loss, it helps to understand how calories and your body’s energy expenditure work.
What is a Calorie?
A calorie is a unit of measurement for energy. When we talk about calories in terms of weight loss, we are referring to kilocalories or what is commonly called Calories (capital C). A Calorie represents the amount of energy required to raise the temperature of 1 kilogram of water by 1 degree Celsius.
Calories are found in all foods and beverages. Things like protein, fat, carbohydrates, fiber, and even alcohol contain Calories that can provide the body energy. Calories come from chemical energy stored within bonds that is released when those molecular bonds are broken down during digestion.
How Calories Are Used and Stored
The Calories we consume from foods and drinks are either used fairly immediately to fuel bodily functions and physical activity or get stored within the body for later use. Calories get absorbed from the digestive system into the bloodstream in the form of blood glucose, triglycerides, and amino acids.
From there, some Calories may get transported to cells right away to generate ATP energy that powers physiological processes. Excess Calories beyond what is needed get converted primarily into triglycerides and deposited within fat cells around the body. This fat storage acts as the body’s energy reserves, which get tapped into between meals or during increased energy expenditure.
When Weight Loss Occurs
Weight loss occurs anytime, the body dips into those fat reserves and starts using stored fat for energy. This happens when the Calories being expended start exceeding the Calories being consumed from foods.
Several things account for our daily calorie expenditure, the main components being:
• Basal Metabolic Rate (BMR): The Calories used to fuel basic involuntary bodily functions like breathing, blood circulation, nutrient processing, cell repair, hormone regulation, etc., even at complete rest. This makes up the majority of one’s metabolic rate.
• Physical Activity: Calories burned by all movements and exercise. More strenuous and prolonged activity burns more Calories.
• Thermic Effect of Food: The small boost in Calories burned just through the digestion, absorption, and metabolizing of consumed foods; thermogenic fat burner supplements can expedite this process.
To lose weight, you either have to decrease the Calories going in, or increase the Calories being expended. When the Calories in get low enough, the body makes up the difference by breaking down stored fat to use for energy production. Over time, this calorie deficit leads to weight loss.
The 3,500 Calorie Rule
There is a general rule that to lose 1 pound of fat, you must have a 3,500 Calorie deficit between what you consume and what your body expends. Since 1 pound equals 3,500 grams and fat contains about 9 Calories per gram, reducing Calories by that 3,500 amount translates into about a pound of fat loss.
At a 500 Calorie per day deficit from diet, exercise, or both, it would take roughly 1 week (7 days x 500 Calorie deficit = 3,500 Calorie deficit) to lose 1 pound. This would translate into about a 1-2 pound healthy weight loss per week. Losing weight requires consistency with that caloric deficit over time.
So, in summary, weight loss relies on establishing a calorie deficit through diet and exercise modifications. Understanding Calories and how our bodies utilize energy can help guide healthy approaches to weight management. Tracking Calorie intake and expenditure provides quantifiable data to calibrate the right calorie balance for your goals.
