Your macros for weight loss depend on your body size, activity level, and calorie budget, but a solid starting point for most adults is 30% of calories from protein, 25–30% from fat, and 40–45% from carbohydrates. These ratios shift your diet toward higher protein (which controls hunger and preserves muscle) while keeping enough fat for hormonal health and enough carbs to fuel your daily life. The real key, though, is getting your total calories right first, then dividing them into macros that match your body and goals.
Step 1: Find Your Calorie Target
Before you can split calories into macros, you need to know how many calories your body burns in a day. The most accurate widely available method is the Mifflin-St Jeor equation, which a comparative study found predicts resting metabolic rate within 10% of measured values more reliably than other formulas.
For women, the formula is: (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161. For men, it’s the same but you add 5 instead of subtracting 161. That gives you your resting metabolic rate, the calories your body burns doing absolutely nothing. Then multiply by an activity factor: 1.2 if you’re sedentary, 1.375 if you’re lightly active (walking a few times a week), 1.55 if you’re moderately active (exercising 3–5 days), or 1.725 if you’re very active.
The result is your total daily energy expenditure, or TDEE. To lose about a pound per week, subtract 500 calories from that number. A useful approach from Cleveland Clinic dietitians: aim to burn about 300 of those calories through extra movement and cut only 200 from your food. This keeps your calorie budget more livable and makes the deficit easier to sustain.
Step 2: Set Your Protein
Protein is the most important macro to get right during weight loss. It’s the most filling of the three macronutrients, consistently outperforming fat and carbohydrates for satiety in research studies. It also has the highest thermic effect: your body uses 15–30% of protein’s calories just to digest it, compared to 5–10% for carbs and 0–3% for fat. That means a higher-protein diet slightly increases how many calories you burn each day.
For weight loss with muscle preservation, aim for 1.2 to 2 grams of protein per kilogram of body weight. If you’re mostly sedentary and not doing resistance training, the lower end (1.2 g/kg) is reasonable. If you’re lifting weights or doing other strength work (which you should be, if possible), push toward the higher end. For a 75 kg (165 lb) person, that’s roughly 90–150 grams of protein per day. Since protein has 4 calories per gram, that’s 360–600 calories from protein alone.
Step 3: Set Your Fat
Dietary fat is essential for producing hormones, absorbing vitamins, and keeping your brain functioning well. Cutting it too low causes problems, particularly with reproductive hormones like testosterone and estrogen. The minimum for hormonal health is around 0.8–1 gram of fat per kilogram of body weight. A 70 kg person should eat at least 56–70 grams of fat daily.
In percentage terms, 20–35% of your total calories from fat is the standard range. For weight loss, landing around 25–30% works well for most people. Fat has 9 calories per gram, so it’s calorie-dense. A tablespoon of olive oil is about 14 grams of fat and 120 calories. This means you don’t need large volumes of fatty food to hit your target, but you also can’t afford to be careless with cooking oils, dressings, and nuts if your calorie budget is tight.
Step 4: Fill the Rest With Carbs
Once protein and fat are set, your remaining calories go to carbohydrates. This is why carbs are the most variable macro. They’re calculated last, and the amount you get depends entirely on how much room is left in your calorie budget.
Here’s how that plays out in practice. Say your target is 1,800 calories per day. You set protein at 140 grams (560 calories) and fat at 65 grams (585 calories). That leaves 655 calories for carbs, which at 4 calories per gram is about 164 grams. That’s roughly 36% of your calories from carbs, which falls slightly below the Dietary Guidelines range of 45–65% but is perfectly reasonable for a weight loss phase.
Your activity level should influence how many carbs you eat. People who are physically active with more lean muscle mass tolerate significantly more carbohydrates than sedentary individuals. If you run, cycle, lift weights, or play sports regularly, skimping on carbs will hurt your performance. Athletes in particular need adequate carbohydrate stores to sustain endurance and power output. If you’re mostly sedentary, lower-carb approaches are easier to stick with because your body simply doesn’t demand as much glycogen.
A Worked Example
To make this concrete, here’s a full calculation for a moderately active 35-year-old woman who weighs 70 kg (154 lbs) and is 165 cm (5’5″) tall:
- Resting metabolic rate: (10 × 70) + (6.25 × 165) − (5 × 35) − 161 = 1,370 calories
- TDEE at moderately active (×1.55): about 2,124 calories
- Weight loss target (−500): about 1,624 calories
- Protein at 1.6 g/kg: 112 g = 448 calories (28%)
- Fat at 0.9 g/kg: 63 g = 567 calories (35%)
- Carbs (remainder): 152 g = 609 calories (37%)
Those numbers are workable and sustainable. If she found herself constantly hungry, she could bump protein up and reduce carbs or fat slightly. If her workouts were suffering, she’d add carbs back and trim fat a bit. The framework stays the same; the dials just shift.
Why Fiber Matters Within Your Carbs
Not all carbohydrates are equal for weight loss, and fiber is the reason. A study published in the Annals of Internal Medicine found that people who simply aimed to eat 30 grams of fiber per day lost 4.6 pounds and kept it off for 12 months, even without following any other dietary rules. Those on a more structured diet lost only slightly more (5.9 pounds). Higher fiber intake also improved blood pressure and insulin response in both groups.
Prioritize your carb grams toward vegetables, fruits, legumes, and whole grains rather than refined sources. This makes your carb allotment work harder for you by increasing fullness, slowing digestion, and stabilizing blood sugar.
How To Handle Alcohol
Alcohol contains 7 calories per gram, placing it between carbs (4 cal/g) and fat (9 cal/g). It’s sometimes called the “fourth macro” because it carries calories but provides no nutritional benefit. When you drink, your body prioritizes burning the alcohol and puts fat and carbohydrate metabolism on hold, which is why it’s best tracked as either fat or carbs in your macro budget.
The simplest approach: take the total calories of your drink and divide by 4 to log it as carb grams, or divide by 9 to log it as fat grams. A 150-calorie glass of wine, for example, could be logged as about 38 grams of carbs or 17 grams of fat. Either way, those calories come out of your daily budget.
Adjusting Over Time
Your starting macros are an educated guess. The real information comes from what happens over the next two to four weeks. If you’re losing 0.5–1 pound per week and your energy feels stable, your numbers are working. If you’re losing faster than that, you may be in too steep a deficit, which risks muscle loss. If the scale isn’t moving, your calorie estimate may be too high, or you may be underestimating portions.
As you lose weight, your TDEE drops because there’s less of you to fuel. Expect to recalculate every 10–15 pounds lost. Protein should stay constant or increase slightly (since you want to protect the muscle you have), while carbs and fat absorb the reduction in total calories. This is normal and not a sign that your metabolism is “broken.” It’s just physics: a smaller body burns fewer calories at rest.