Your body needs about 30 different nutrients every day to function properly, and nearly all of them can come from food. These fall into three categories: macronutrients (protein, carbohydrates, and fat), which provide energy; micronutrients (vitamins and minerals), which support everything from immune function to bone strength; and water plus electrolytes, which keep your cells and organs in balance. Here’s what to aim for and where to find it.
The Three Macronutrients
Macronutrients are the calorie-providing nutrients your body uses for energy, tissue repair, and basic biochemistry. Federal dietary guidelines set acceptable ranges as a percentage of your total daily calories: 45 to 65 percent from carbohydrates, 20 to 35 percent from fat, and 10 to 35 percent from protein. Eating consistently outside these ranges increases the risk of both chronic disease and nutrient insufficiency.
In practical terms, if you eat roughly 2,000 calories a day, that translates to about 225 to 325 grams of carbohydrates, 44 to 78 grams of fat, and 50 to 175 grams of protein. Most people land somewhere in the middle of those ranges without much effort, but the quality of each macronutrient matters just as much as the quantity.
How Much Protein You Actually Need
The baseline recommendation for adults is 0.8 grams of protein per kilogram of body weight per day. For a 150-pound (68 kg) person, that’s about 54 grams. This is enough to prevent deficiency, but it may not be enough to maintain muscle mass as you age. Research from UC Davis notes that 0.8 g/kg is likely too low for older adults to preserve lean body mass over time.
If you exercise regularly, your needs go up. Endurance athletes benefit from 1.2 to 1.4 g/kg per day, while strength and power athletes do best between 1.4 and 1.8 g/kg per day. For that same 150-pound person, the upper end would be about 122 grams daily. Good sources include poultry, fish, eggs, dairy, beans, lentils, and tofu.
Carbohydrates and Fiber
Carbohydrates are your body’s preferred fuel source, especially for your brain and muscles during exercise. The key distinction is between refined carbohydrates (white bread, sugary drinks, pastries) and complex carbohydrates (whole grains, vegetables, legumes, fruit). Complex carbs deliver energy along with fiber, vitamins, and minerals. Refined carbs deliver mostly calories.
Fiber deserves special attention because most people fall short. The adequate intake is 25 grams per day for women and 38 grams for men. Fiber supports digestion, feeds beneficial gut bacteria, and helps regulate blood sugar and cholesterol. Vegetables, fruits, whole grains, beans, lentils, nuts, and seeds are the richest sources.
Fats: Quality Over Quantity
Fat is essential for absorbing certain vitamins, producing hormones, and protecting your organs. But the type of fat you eat has a bigger health impact than the total amount. Saturated fat, found primarily in red meat, butter, cheese, and coconut oil, should stay below 10 percent of your daily calories. On a 2,000-calorie diet, that’s about 22 grams or less. Replacing saturated fat with unsaturated fat from sources like olive oil, avocados, nuts, and fatty fish consistently lowers cardiovascular risk.
One fat your body cannot make on its own is alpha-linolenic acid, a plant-based omega-3 fatty acid. Men need about 1.6 grams per day and women need 1.1 grams. You can get this from walnuts, flaxseed, chia seeds, and canola oil. Fatty fish like salmon and sardines provide other forms of omega-3s that your body uses more efficiently.
Vitamins Your Body Needs Daily
There are 13 essential vitamins, each with a specific role. You don’t need to track all of them individually if you’re eating a varied diet with plenty of vegetables, fruits, whole grains, and protein sources. But a few are worth knowing about because deficiencies are common.
Vitamin D is one of the hardest to get from food alone. Adults up to age 70 need 600 IU (15 mcg) per day, and those over 70 need 800 IU (20 mcg). Your skin produces vitamin D from sunlight, but people who live in northern climates, spend most of their time indoors, or have darker skin often fall short. Fatty fish, fortified milk, and egg yolks provide some, but supplementation is common.
The B vitamins (there are eight of them) work together to convert food into energy, build red blood cells, and maintain your nervous system. Whole grains, meat, eggs, legumes, and leafy greens cover most of them. Vitamin B12 is found almost exclusively in animal products, so people following a fully plant-based diet need a supplement or fortified foods. Folate (B9) is critical during pregnancy for preventing neural tube defects, and it’s abundant in leafy greens, beans, and fortified grains.
Vitamin C supports immune function and helps your body absorb iron from plant foods. Citrus fruits, bell peppers, strawberries, and broccoli are all rich sources. Vitamins A, E, and K round out the list: orange and dark green vegetables deliver vitamin A, nuts and seeds provide vitamin E, and leafy greens are the primary source of vitamin K.
Essential Minerals
Minerals are divided into two groups. Major minerals are needed in larger amounts, while trace minerals are needed in tiny quantities but are equally important.
Calcium
Adults over 24 need about 800 mg per day, while those aged 11 to 24 need 1,200 mg to support bone development. Dairy products are the most concentrated source, but fortified plant milks, canned sardines (with bones), tofu made with calcium sulfate, and leafy greens like kale and bok choy all contribute.
Magnesium
Women need about 280 mg daily and men need about 350 mg. Magnesium plays a role in over 300 enzyme reactions, including muscle function, blood sugar regulation, and sleep quality. Brazil nuts, cashews, peanuts, spinach, black beans, and whole grains are reliable sources. Many adults fall below the recommended intake without realizing it.
Iron
Iron carries oxygen in your blood. Premenopausal women need 18 mg per day due to menstrual losses, while men and postmenopausal women need 8 mg. Iron from animal sources (red meat, poultry, shellfish) is absorbed about two to three times more efficiently than iron from plant sources. If you rely on plant foods for iron, eating them alongside vitamin C-rich foods significantly improves absorption. Cashew nuts and green lentils rank among the most bioavailable plant sources of iron.
Zinc and Other Trace Minerals
Zinc supports immune function, wound healing, and your sense of taste and smell. Men need 11 mg per day, women need 8 mg. Green lentils, cashews, and buckwheat groats are strong plant sources. Oysters, beef, and crab provide the highest concentrations overall.
One thing to be aware of: plant foods that are rich in minerals also contain compounds like phytates and oxalic acid that bind to those minerals and reduce absorption. Soaking, sprouting, or fermenting grains and legumes before cooking breaks down some of these compounds and makes the minerals more available to your body.
Water and Electrolytes
Total water intake (from drinks and food combined) should be about 3.7 liters per day for men and 2.7 liters for women. Roughly 20 percent of that comes from food, so men need about 13 cups of beverages and women need about 9 cups. These numbers increase with heat, exercise, and altitude.
Electrolytes keep your fluid balance, nerve signaling, and muscle contractions working properly. Potassium is the one most people fall short on: the adequate intake is 4.7 grams per day, and most adults get well under that. Bananas get all the credit, but potatoes, beans, spinach, yogurt, and avocados actually deliver more potassium per serving. Sodium intake for adults is set at 1.5 grams per day as the adequate intake, though most people consume far more than that from processed and restaurant foods.
What to Limit
Two nutrients are worth capping rather than boosting. Added sugars should stay below 10 percent of your daily calories, which is about 50 grams (12 teaspoons) on a 2,000-calorie diet. Sweetened beverages, flavored yogurts, cereals, sauces, and baked goods are the main contributors. Saturated fat also has a 10-percent ceiling, as noted above. These aren’t nutrients to eliminate entirely, but consistently exceeding these thresholds raises your risk of heart disease, type 2 diabetes, and obesity.
Putting It Together
You don’t need to hit every single target every day. Nutrient needs average out over the course of a week, so a day with less calcium or fiber isn’t a problem if the rest of your week makes up for it. The most reliable strategy is a diet built around vegetables, fruits, whole grains, legumes, nuts, and a mix of protein sources. That pattern naturally covers most vitamins, minerals, and fiber without needing to micromanage numbers.
Where gaps tend to show up, even in otherwise good diets, is vitamin D, magnesium, potassium, fiber, and omega-3 fats. If you notice you consistently skip entire food groups (no dairy, no fish, no leafy greens), those are the nutrients worth checking on through bloodwork or a targeted supplement.