Complete Guide: Food Calories and Nutrition
What are calories?
Calories (kcal) are the unit of measurement for the energy that food provides to the body. When you eat, your body breaks down food and uses this energy for all its functions: breathing, thinking, moving, and maintaining body temperature.
Each person needs a different amount of daily calories depending on their age, sex, weight, height, and physical activity level.
Macronutrients: the three pillars of nutrition
Protein = 4 kcal/g | Carbohydrates = 4 kcal/g | Fat = 9 kcal/g
Protein
Proteins are essential for building and repairing tissues, producing enzymes, and hormones. Main sources: meat, fish, eggs, legumes, and dairy.
Carbohydrates
Carbohydrates are the body's primary energy source. They're divided into simple (sugars) and complex (starches and fiber). Sources: grains, bread, pasta, fruits, and vegetables.
Fat
Fats are necessary for absorbing vitamins, protecting organs, and producing hormones. Healthy fats (unsaturated) are found in avocado, nuts, and olive oil.
The importance of fiber
Fiber is a type of carbohydrate that the body doesn't digest. It helps maintain a healthy digestive system, control blood sugar, and reduce cholesterol. The recommended intake is 25-35 grams daily.
How to use this calculator
- Search for the food by typing its name or browsing categories
- Select the food from the list to see its nutritional values
- Adjust the portion in grams according to your needs
- Check the macros to plan your diet
Common portion sizes
- A closed fist ≈ 1 cup of rice or pasta
- Your palm ≈ 1 serving of meat (3-4 oz)
- Your thumb ≈ 1 tablespoon of butter
- A handful ≈ 1 serving of nuts (1 oz)
Recommended macro distribution
For a balanced diet, general guidelines suggest:
- Protein: 10-35% of total calories
- Carbohydrates: 45-65% of total calories
- Fat: 20-35% of total calories
| Goal | Protein | Carbs | Fat | |------|---------|-------|-----| | Maintenance | 20% | 50% | 30% | | Weight loss | 30% | 40% | 30% | | Muscle gain | 30% | 45% | 25% |
Frequently asked questions
Calories (kcal) measure the energy that food provides to the body. They matter because consuming more calories than you burn leads to weight gain, while consuming fewer leads to weight loss.
Macronutrients are protein, carbohydrates, and fat. They are nutrients the body needs in large amounts. Protein and carbs provide 4 kcal per gram, while fat provides 9 kcal per gram.
It depends on factors like age, sex, weight, height, and activity level. Generally, adult women need 1,800-2,400 kcal and men need 2,200-3,000 kcal daily.
Fiber is a non-digestible carbohydrate that aids digestion and satiety. The recommended intake is 25-35 grams daily. It's found in fruits, vegetables, whole grains, and legumes.
Values are approximations based on standard USDA data. Actual nutritional composition may vary by brand, preparation method, food ripeness, and geographic origin.
Track the foods you eat to know your total caloric intake. Compare with your daily caloric expenditure (you can calculate it with our TDEE calorie calculator) and adjust to create a moderate deficit of 300-500 kcal.
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