This calorie calculator works by estimating your total daily energy expenditure, or TDEE, and measuring it against your weight goal. TDEE, which is expressed as an average number of calories, includes the amount of energy required to perform basic bodily functions at rest (breathing, blinking) combined with the energy expended by your activities (workouts, walking to the water cooler). To gain weight, eat more calories than your TDEE. To lose weight, eat fewer calories. An aggressive calorie deficit can help you lose weight fater, but it can also make you hungry, sap your energy. If you feel this way following the calorie calculator’s recommended target, increase your calories by 200 and reevaluate how you feel after a week. Your results may take longer to show up, but it will feel like less of a struggle and you’ll be more likely to maintain your progress. Conversely, if you feel like the target gives you more than enough to eat and you’re not seeing results, try adjusting the target down slightly and eating less. TDEE = total daily energy expenditure.
Human metabolism is complex, and gaining or losing weight takes more than hitting your calorie goal. Fat, protein, and carbohydrates all have different nutrient functions in the body, and an effective diet will include at least a little of all three macronutrients. Protein builds muscle and maintains other body tissue. Fat provides energy, regulates hormone production, and keeps you full. Carbohydrates also provide energy and help you sleep at night. Theoretically, eating fewer calories than you expend can help you lose weight, but the type of calories you eat influences your results. For example, if you eat very low-carb and have trouble sleeping, your hunger levels could rise and you might struggle to keep your calorie intake low enough to lose weight. Or if you don’t eat enough calories from fat or carbs to power your workouts, you could end up burning fewer calories than you think, because you’re not giving it your all in the gym. Fat, protein, and carbohydrates are all metabolized differently and are converted into body weight with different rates of efficiency. Protein and carbohydrates each provide 4 calories per gram, while fat provides 9 calories per gram.
You need to eat fewer calories than you burn to lose fat. However, if you restrict your energy intake for too long, this can eventually slow your metabolism in a process called "metabolic adaptation," which makes it difficult to continue losing weight. To combat metabolic adaptation, you can use a strategy called "reverse dieting," in which you gradually increase your caloric intake in order to raise your metabolism. Even though it sounds a little crazy to increase calories to lose weight, this ultimately helps you burn more calories. To create an effective reverse diet, you may also need to do less cardio and more heavy lifting, which will further optimise your metabolism to build muscle and shed fat. If you’ve reached a point with your dieting where you think you may need to reverse diet, do it strategically to maximise your results.