Creating a diet plan starts with one number: how many calories your body burns in a day. Everything else, from what you eat to how much, builds on that foundation. The process isn’t complicated, but each step matters. Here’s how to build a plan you can actually follow.
Calculate Your Daily Calorie Target
Your body burns a baseline number of calories just by existing: breathing, circulating blood, maintaining body temperature. This is your resting metabolic rate, and the most accurate way to estimate it is the Mifflin-St Jeor equation. For men, the formula is (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5. For women, it’s the same formula but you subtract 161 instead of adding 5.
That gives you a resting number. To get your actual daily burn, multiply by an activity factor:
- Sedentary (desk job, little exercise): multiply by 1.2
- Lightly active (light exercise 1-3 days/week): multiply by 1.375
- Moderately active (moderate exercise 3-5 days/week): multiply by 1.55
- Very active (hard exercise 6-7 days/week): multiply by 1.725
The result is your total daily energy expenditure, or TDEE. To lose weight, eat roughly 500 calories below that number, which works out to about one pound of fat loss per week. To gain weight, add 250 to 500 calories above it. To maintain, eat at that number. A 35-year-old woman who weighs 70 kg (154 lbs), stands 165 cm (5’5″), and exercises moderately would have a TDEE around 2,050 calories. For weight loss, she’d aim for about 1,550 per day.
Divide Your Calories Into Macronutrients
Once you have a calorie target, split it into three categories: protein, carbohydrates, and fat. The Dietary Guidelines for Americans recommend 10 to 35% of calories from protein, 45 to 65% from carbohydrates, and 20 to 35% from fat. Those are wide ranges, so here’s how to narrow them down based on your goals.
Start with protein, since it’s the nutrient most people undershoot. The baseline recommendation is 0.8 grams per kilogram of body weight per day, but that’s the minimum to avoid deficiency, not the amount for optimal body composition. If you do strength training, aim for 1.4 to 1.8 grams per kilogram. For a 70 kg person, that’s 98 to 126 grams of protein daily, which translates to roughly 25 to 30% of a 1,600-calorie diet.
After protein, set fat at around 25 to 30% of total calories. Fat supports hormone production and helps you absorb certain vitamins, so going too low (below 20%) can backfire. Whatever calories remain go to carbohydrates. For most people following a moderate plan, this naturally lands around 40 to 50% of calories from carbs, which provides enough fuel for daily activity and exercise.
Each gram of protein has 4 calories, each gram of carbohydrate has 4 calories, and each gram of fat has 9 calories. So on a 1,600-calorie plan with 30% protein, 30% fat, and 40% carbs, you’d aim for roughly 120 grams of protein, 53 grams of fat, and 160 grams of carbohydrates per day.
Choose Foods That Keep You Full
A diet plan that leaves you constantly hungry won’t last. The foods you choose matter almost as much as the numbers. Research from the University of Sydney ranked common foods by how full they keep people over two hours compared to white bread. Boiled potatoes scored highest at 323% of the white bread baseline, meaning they kept people satisfied more than three times as long. Croissants scored lowest at 47%. In general, foods that are high in fiber, water, and protein rank highest for satiety, while fatty, refined baked goods rank lowest.
Build your meals around whole foods that earn their calories. Lean proteins like chicken breast, fish, eggs, and legumes deliver a lot of nutrition per calorie. Vegetables are extremely low in calories but high in volume, so they physically fill your stomach. Whole grains, potatoes, and oats provide sustained energy. Healthy fats from nuts, olive oil, and avocado are calorie-dense, so a little goes a long way, but they add flavor and keep meals satisfying.
Plan Your Portions Without a Scale
You don’t need to weigh every meal. Your hands provide a surprisingly reliable measuring system that scales to your body size. A palm-sized portion of meat, chicken, or fish is roughly 3 ounces of cooked protein. A closed fist equals about one cup of cooked vegetables or grains. Your thumb, from tip to base, is roughly one tablespoon, useful for measuring dressings and nut butters. The tip of your thumb is about one teaspoon, which is a standard portion for butter or oil.
A practical plate at lunch or dinner might look like this: one palm of protein, one to two fists of vegetables, one fist of a starchy carb (rice, potato, or pasta), and one thumb of added fat. That structure keeps your macros roughly balanced without tracking every gram. If you prefer more precision, use a food tracking app for the first two to three weeks to calibrate your eye, then transition to the hand method once you’ve internalized portion sizes.
Structure Your Meals for the Day
There’s no metabolic magic to eating three meals versus six. Clinical evidence shows no significant difference in metabolic rate between fewer large meals and more frequent small ones, as long as total daily calories are the same. What matters is picking a pattern that fits your schedule and prevents you from getting so hungry that you overeat.
Most people do well with three meals and one or two small snacks. If your calorie target is 1,600, that might look like 400 calories at breakfast, 450 at lunch, 500 at dinner, and 250 spread across snacks. You can shift those numbers based on when you’re hungriest. If mornings are easy but evenings are when cravings hit, keep breakfast lighter and save more calories for a satisfying dinner.
A sample day on a 1,600-calorie plan could be: oatmeal with berries and a boiled egg for breakfast (roughly 400 calories), a grain bowl with chicken, roasted vegetables, and a drizzle of olive oil for lunch (450 calories), a snack of Greek yogurt with a handful of almonds (250 calories), and salmon with sweet potato and a large green salad for dinner (500 calories).
Watch Sodium, Sugar, and Fiber
Three numbers tend to drift out of range when people aren’t paying attention. The World Health Organization recommends staying under 2,000 mg of sodium per day, which is less than a teaspoon of salt. Most processed and restaurant food blows past this easily. Cooking at home and seasoning with herbs, spices, and citrus instead of salt makes a significant difference.
Added sugars should stay modest. They contribute calories without filling you up or providing vitamins. Sweetened drinks, flavored yogurts, sauces, and packaged snacks are the biggest sources. Reading ingredient lists catches hidden sugars listed under names like dextrose, maltose, or rice syrup.
Fiber is the nutrient most people fall short on. Adult women need about 25 grams per day and men need about 38 grams. Fiber slows digestion, steadies blood sugar, and feeds beneficial gut bacteria. Beans, lentils, whole grains, vegetables, fruits, and nuts are the richest sources. If your current intake is low, increase it gradually over a week or two to avoid bloating.
Stay Hydrated
Water needs vary by body size, climate, and activity level, but a reasonable starting point is 11.5 cups (2.7 liters) for women and 15.5 cups (3.7 liters) for men from all fluid sources combined, including food. Fruits, vegetables, soups, and other water-rich foods contribute meaningfully to that total. If your urine is pale yellow, you’re generally drinking enough. Dark yellow or amber means you need more.
Build in Flexibility
The biggest predictor of whether a diet plan works is whether you stick with it. A landmark study on dieting strategies found that flexible approaches, where you aim for targets most of the time but allow room for occasional indulgences, were associated with lower body mass, less overeating, and reduced levels of depression and anxiety. Rigid restraint, where foods are strictly forbidden and rules are absolute, was linked to more binge eating and higher body weight over time.
In practice, this means building treats into your plan rather than banning them. If you eat well 80 to 90% of the time, the occasional slice of pizza or dessert won’t derail your progress. Planning a weekly meal where you eat what you enjoy, without guilt, makes the other six days easier to sustain. A diet plan that works for three months beats a perfect plan you abandon after two weeks.
Adjust as You Go
Your starting plan is an educated estimate, not a permanent prescription. Track your weight weekly (same time, same conditions) and look at the trend over two to four weeks rather than day-to-day fluctuations. If you’re trying to lose weight and the scale hasn’t moved after three weeks, reduce your daily intake by 100 to 200 calories or add a bit more activity. If you’re losing faster than one to two pounds per week and feeling drained, add calories back.
As your weight changes, your calorie needs change too. A person who loses 10 kg burns fewer calories at rest than they did before, simply because there’s less body to fuel. Recalculate your TDEE every 10 to 15 pounds of weight change and adjust your plan accordingly. This recalibration is normal and expected, not a sign that something is wrong.