How to set up your diet for your goals
Your training decides the stimulus and your diet decides what your body does with it. Whether you want to lose fat, build muscle or hold steady, it comes down to how much energy you eat relative to how much you burn, plus enough protein to protect or build muscle. Everything else sits on top of those two things.
This guide walks through choosing a goal, setting a sensible starting point, and adjusting based on what really happens over a few weeks rather than trusting any calculator to be perfect. It pairs with our calorie calculator, which gives you the starting numbers.
Pick one direction at a time
You can lose fat, build muscle at your best rate, or maintain, but you can only fully prioritise one at a time, because losing fat needs an energy deficit and building muscle is best served by an energy surplus. Doing both at once, the eternal recomp dream, is possible for beginners and people returning from a break. It is slow, and for everyone else it means doing both jobs at half speed.
Choose a direction and commit to it for a block of months rather than days. A sensible common pattern: if you're carrying more fat than you'd like, run a fat-loss phase first to get lean, then switch to a muscle-building phase. If you are already lean, start by building. Chasing whichever goal you feel like each week is how people spend a year going nowhere.
Setting your calories
Start from your maintenance level, the calories that keep your weight stable, which our calorie calculator estimates from your body stats and activity. To lose fat, eat below it. A deficit of around 15 to 20%, very roughly 300 to 500 calories a day for many people, drives steady fat loss of about 0.5 to 1% of bodyweight per week, which is sustainable and muscle-sparing. To build muscle, eat slightly above maintenance, and a small surplus of around 10%, a few hundred calories, supports growth without piling on excess fat. To maintain, eat around maintenance and let performance guide small tweaks.
Resist the urge to be aggressive. A brutal deficit costs you muscle, energy and adherence, and a huge surplus adds fat you will have to lose later. A moderate plan you can sustain for months beats an extreme one you quit in two weeks, which describes most failed diets.
Every calorie number from any calculator is an estimate, and individual metabolism varies by 10 to 20%. Treat your starting figure as a hypothesis to test over three to four weeks.
Protein first, then the rest
Once calories are set, protein is the macronutrient to lock in. Aim for roughly 1.6 to 2.2 g per kg of bodyweight per day, leaning higher when you're in a deficit to protect muscle. It is also the most filling nutrient, which makes a diet far easier to stick to. After protein, the split between carbs and fats is largely down to preference and performance, and there is no magic ratio. Keep fats high enough for health, with a common floor around 0.5 to 0.8 g/kg, and fill the rest of your calories with carbohydrates, which fuel hard training.
Hit your calorie target, hit your protein, keep fats reasonable, and let carbs make up the balance. Chasing precise macro percentages beyond this adds effort without adding results for almost everyone.
Adjust by what actually happens
This step separates people who progress from people who spin their wheels. Set your numbers, then track two things for three to four weeks: your bodyweight as a weekly average, since daily weight swings with water and food, and roughly how you're eating. Then read the trend. Losing weight too fast, or feeling wrecked? Add a little food. Not losing at all on a fat-loss phase? Your real maintenance is lower than estimated, so trim slightly. Gaining fat quickly on a muscle phase? Ease the surplus back.
The calculator gives you a starting point, and your own results over a month give you the truth. Adjust in small steps, give each change a few weeks to show, and you will converge on numbers that fit your body. Set, measure, adjust is the entire skill of diet, and it is far more reliable than any formula.
Durata syncs your daily calories and protein from Apple Health or Health Connect, logged in whatever food app you use, and shows them alongside your body-weight trend and training, so the feedback you need to judge your plan sits in one place.
Common questions
How many calories should I eat to lose fat?
Start about 15 to 20% below your maintenance calories, very roughly 300 to 500 fewer per day for many people, which drives steady fat loss of around 0.5 to 1% of bodyweight a week. Estimate maintenance with a calorie calculator, then adjust based on your actual results over a few weeks.
How many calories to build muscle?
A small surplus of around 10% above maintenance, a few hundred extra calories a day, supports muscle growth without adding much fat. Bigger surpluses add fat you will have to lose later, since muscle can only be built so fast.
Can I build muscle and lose fat at the same time?
Beginners and people returning after a break often can, slowly. For most trained people it is more effective to pick one goal at a time, a fat-loss phase or a muscle-building phase, since the two pull calories in opposite directions.
What macros should I eat?
Set protein first, about 1.6 to 2.2 g/kg of bodyweight, keep fats high enough for health at roughly 0.5 to 0.8 g/kg minimum, and fill the rest with carbs to fuel training. Beyond that, exact carb-to-fat ratios are down to preference.
Are calorie calculators accurate?
They give a good starting estimate, but individual metabolism varies by 10 to 20%, so no calculator is exact for you. Use the number as a hypothesis, track your weight trend for three to four weeks, and adjust up or down based on what actually happens.
Put it into practice
Durata is free to use — 50 proven programs, automatic progression, rest timers and PR tracking, all on your phone.