Biology
Core Concepts in Nutrition
Quick fact
The human body requires more than 40 essential nutrients—that the body cannot produce on its own—which must come from food or supplements.
Why this is interesting
You have likely heard that 'you are what you eat,' but have you ever wondered how your body knows what to do with the food you consume? The answer lies in a handful of core concepts that govern nutrition.
Read the full explanation
Understanding Core Concepts in Nutrition
At its simplest, nutrition is about what your body gets from food and how it uses those materials. The core concepts begin with macronutrients: carbohydrates, proteins, and fats. These provide energy (calories) and serve as building blocks for cells. Carbohydrates are the body's preferred fuel, proteins repair tissues, and fats support cell membranes and hormone production. Micronutrients—vitamins and minerals—are needed in smaller amounts but are vital for processes like bone health, immune function, and energy release. Energy balance compares calories consumed to calories burned; a surplus leads to weight gain, a deficit to weight loss. Metabolism refers to the chemical reactions that convert food into energy and cellular components. Understanding these basics helps explain why diets recommend variety and moderation.
A deeper explanation
These core concepts work because they are rooted in biochemistry and physiology. Macronutrients are broken down during digestion into simple molecules (e.g., glucose, amino acids, fatty acids) that enter metabolic pathways. For instance, glucose undergoes glycolysis and the citric acid cycle to produce ATP, the cell's energy currency. Essential nutrients are those the body cannot synthesize, so they must be provided by diet—this includes certain amino acids, fatty acids, vitamins, and minerals. Dietary Reference Intakes (DRIs) are evidence-based guidelines that specify daily amounts of nutrients for different populations. The concept of nutrient density compares the nutrient content of a food to its calorie load; whole foods like vegetables and lean proteins are high in nutrients per calorie, while processed foods tend to be low. These principles matter because they form the scientific basis for dietary recommendations (e.g., MyPlate) and help explain the links between diet, chronic disease, and overall health.