This is not medical advice. These are population ranges, not a plan written for you. If you are under 18, pregnant or breastfeeding, have ever had a difficult relationship with food, or are managing a medical condition, talk to a doctor or a registered dietitian before changing what you eat. The full list is here.
What are macronutrients?
Macronutrients, or macros, are the three categories of nutrient that carry energy. Every food is some combination of them, and the conversion factors are fixed:1 protein and carbohydrate give you 4 kcal per gram, fat gives you 9. Those are the Atwater factors, and they're why any macro split can be turned into grams and back again. Alcohol is a fourth at 7 kcal per gram. It just isn't a nutrient.
Most macro guides skip the part that matters: there are official ranges, and they aren't the ones fitness sites quote. The US National Academies publish Acceptable Macronutrient Distribution Ranges, or AMDR, which are the shares of energy associated with a lower risk of chronic disease while still meeting your nutrient needs.2
| Macro | AMDR (% of daily energy) | On a 2,000 kcal day |
|---|---|---|
| Protein | 10 to 35% | 50 to 175 g |
| Carbohydrate | 45 to 65% | 225 to 325 g |
| Fat | 20 to 35% | 44 to 78 g |
Keep that table in mind. A lot of popular splits fall outside it, and I'll come back to which ones.
Protein: the building block
Protein earns most of the attention it gets, for four reasons that vary a lot in how solid they are.
It builds and repairs muscle, which is why resistance training works at all. It protects muscle in a deficit: when you're eating less than you burn, how much protein you get decides how much of the loss comes off as fat rather than lean tissue.4 Gram for gram it also keeps you fuller than carbs or fat, which makes a deficit easier to stick to.4
The fourth reason gets oversold. Digesting protein costs 20 to 30% of the energy it contains, against 5 to 10% for carbohydrate and almost nothing for fat.3 That's real, and on a high-protein day it's worth maybe 80 to 100 kcal. Useful. Not the metabolic loophole it gets sold as.
How much protein, and where 1.6 g/kg actually comes from
You'll see "1.6 to 2.2 g per kg of bodyweight" quoted everywhere without a source. It does have one. A meta-analysis of 49 resistance-training trials with 1,863 participants found that intakes above roughly 1.62 g/kg/day produced no further gains in fat-free mass.5 Read that again, because it's the opposite of how the number usually gets used: 1.6 g/kg is where the benefit stops, not where it starts. The top of the popular range is a safety margin.
That breakpoint is a central estimate with a wide interval around it rather than a hard line, and the number is scaled to bodyweight, which is not the only option. Why macro calculator apps disagree about your protein target goes through what the meta-analysis actually reported and why the published recommendations range from 0.8 to over 3 g/kg.
A practical target is around 1.6 g per kg of bodyweight if you train, so roughly 112 g a day for a 70 kg person. Going higher won't hurt healthy kidneys, but the meta-analysis says you're unlikely to get more muscle for the trouble. If you're in a deficit or over about 60, sit nearer the top of the range than the bottom, because both of those make muscle harder to hold onto.4
The catch nobody mentions: g/kg and % of calories disagree
Both framings are in common use, and they can contradict each other. Take a 70 kg person eating 1,600 kcal in a deficit. At 1.6 g/kg that's 112 g of protein, which works out at 448 kcal, or 28% of the day. Fine. Now take a 100 kg person eating 1,500 kcal. The same 1.6 g/kg is 160 g, or 640 kcal, which is 43% of energy and well past the AMDR ceiling of 35%.
Neither number is wrong. They answer different questions. The g/kg target is about muscle, the AMDR is about not crowding out everything else. When they conflict the usual resolution is to keep protein high and accept the percentage, but it's a decent reason not to treat any single split as gospel, and a good reason to raise it with a dietitian if you're eating aggressively low.
For sources, the usual suspects work: chicken breast, eggs, Greek yoghurt, cottage cheese, fish, lean beef, tofu, tempeh, lentils. Protein powder counts too if convenience is the thing standing in your way.
Carbohydrates: your primary fuel
Carbohydrates have been unfairly demonized by fad diets for decades. The reality is duller. Carbs are your body's preferred energy source, especially for the brain and during hard exercise, and what matters is which ones you eat.
| Quality carbs | Low-quality carbs |
|---|---|
| Oats, brown rice, quinoa | White bread, pastries |
| Sweet potatoes, vegetables | Candy, soda, juice |
| Fruits, legumes | Chips, cookies |
| Whole grain pasta/bread | Processed cereals |
The left column comes with fibre, vitamins and minerals. Those foods digest slowly and keep blood sugar steadier. The right column digests fast and leaves you hungry again an hour later.
That distinction isn't just intuition. A series of systematic reviews and meta-analyses commissioned by the WHO, covering 185 prospective studies and 58 clinical trials across nearly 135 million person-years, found that people eating the most dietary fibre had a 15 to 30% lower risk of all-cause and cardiovascular mortality, coronary heart disease, type 2 diabetes and colorectal cancer than those eating the least.6 The dose-response curves put the intake to aim for at 25 to 29 g of fibre a day, with signs that more is better still.
So the case for carb quality is really a case about fibre and whole grains rather than carbohydrate as a category. It's also why "low carb" and "healthy" aren't synonyms. Cutting carbs cuts fibre unless you go out of your way to stop it.
One correction to the usual advice, from the same paper. The evidence for glycaemic index and glycaemic load was graded low to very low and showed smaller or no risk reductions.6 Fibre and whole grains were graded moderate. If you're only going to optimise one thing about your carbohydrates, optimise the fibre. The GI charts are a much weaker signal than their popularity suggests.
Practical rule: if it came from the ground or a tree and still looks roughly like it did, it's probably a quality carb. Failing that, read the fibre figure on the label rather than the sugar one. 25 to 29 g a day is what the evidence points at,6 and most people eat about half that.
Fat: essential, not the enemy
For decades dietary fat was blamed for making people fat, which turned out to be a dramatic oversimplification. You need fat to produce hormones, to absorb vitamins A, D, E and K, and to keep cell membranes and brain tissue working. It's also your fuel for long, low-intensity effort, and it slows digestion enough to keep you satisfied after a meal.
The type matters more than the amount. The American Heart Association's 2017 review of the trial evidence found that replacing saturated fat with polyunsaturated fat lowered cardiovascular disease by about 30%, comparable to what statins achieve, while replacing it with refined carbohydrate did nothing at all.7 The word doing the work there is replacing. What you swap saturated fat for decides whether the swap helps you.
In practice: favour olive oil, rapeseed oil, avocados, nuts, seeds and oily fish. Limit fatty meat, butter, full-fat dairy, coconut and palm oil. Avoid partially hydrogenated oils altogether, which is getting easier, because the WHO has been pushing to eliminate industrial trans fat from the food supply and many countries have now banned it.8
How to split your macros
There's no single perfect ratio, and the best split is the one you'll actually keep to. But "no perfect ratio" isn't the same as "anything goes." A split should sit inside the AMDR unless you have a specific reason for it not to.
Here is what MyPlate uses, and where each figure lands in its range:
| Goal | Protein (AMDR 10 to 35%) | Carbs (45 to 65%) | Fat (20 to 35%) |
|---|---|---|---|
| Weight loss | 28% | 45% | 27% |
| Maintain | 25% | 47% | 28% |
| Weight gain | 25% | 49% | 26% |
For macro tracking for weight loss, protein sits in the upper half of its range and carbohydrate sits at the very bottom of its own. That's the direction the evidence points, and the AMDR floor is where it stops. Our calorie calculator runs the same splits in your browser if you want the grams for your own numbers rather than mine.
On a 2,000 kcal day at 28% / 45% / 27%, that comes out at 140 g of protein (560 kcal ÷ 4), 225 g of carbs (900 ÷ 4) and 60 g of fat (540 ÷ 9).
Why this is lower in protein than the split you'll find elsewhere
Search for a cutting split and you'll be handed something like 40% protein, 30% carbs, 30% fat. That's 40% protein against an AMDR ceiling of 35%, and 30% carbohydrate against a floor of 45%. Outside the published ranges on both counts.
It isn't necessarily dangerous. Higher-protein, lower-carbohydrate diets are well studied for weight loss and there's a genuine argument for them.4 But it is a departure from a national-academy recommendation, and it's almost always presented without saying so. I hold to the ranges for two reasons. The app tells every user, with a citation, that its numbers sit inside them. And if you're going to depart from a public health recommendation, that should be your decision, made knowingly and ideally with a dietitian, rather than one an app quietly makes for you.
Ketogenic splits go further still, typically 5 to 10% carbohydrate and 60 to 70% fat. Keto is a therapeutic diet with real clinical uses and real supervision requirements. MyPlate doesn't produce a keto split, and this article isn't the place to talk you into one.
Tracking macros in practice
Doing this by hand is tedious enough that most people give up, which is what any macro tracking app is really for. In MyPlate your daily targets come from your profile and goal using the splits above, logging a meal by photo or description breaks it into protein, carbs and fat, and three rings on the home screen show how much of each you've had. You spend the rest of the day against what's left.
Two honest caveats about any macronutrient tracker, mine included. A photo estimate splits a meal into macros with less confidence than it totals the calories, and cooking oil is the reason: it's invisible in a photo and it lands entirely in the fat column, so under-reported fat is the standard failure mode. Second, the targets any app gives you are population formulas, not a plan written for your body.
Don't chase the numbers daily. Macro targets are a weekly average, not a nightly exam. Protein is the one worth hitting most days, because muscle retention responds to what you actually ate. Carbs and fat can swing around quite a bit without anything going wrong. Land near your calorie target with your protein in and the split has done its job.
Common questions
Do macros matter more than calories?
No. Calories decide the direction your weight moves. Macros decide the composition of that change and how bearable it is. Enough protein means more of what you lose is fat rather than muscle,4 and enough fibre means you aren't hungry all day.6 If you can only track one number, track calories. If you can track two, add protein.
Is more protein always better?
Not for muscle. The meta-analysis found no additional gain in fat-free mass above about 1.62 g/kg/day.5 Higher intakes aren't harmful for healthy kidneys, but they aren't buying more muscle either, and past 35% of energy they start crowding out carbohydrate and fibre you'd rather have kept.
Should I use grams per kilo, or percentages?
Grams per kilo for protein, percentages for the rest. Your protein need scales with your body rather than with whatever you happen to be eating that week, so a percentage target quietly drops your protein at the exact moment you cut calories. Carbs and fat work better as shares of energy, which is how the AMDR states them.2
What about keto or very-low-carb diets?
They work for some people, and they sit well outside the AMDR at 5 to 10% carbohydrate against a 45% floor. That doesn't make them wrong. It makes them a considered decision rather than a default, and it means paying close attention to fibre. MyPlate doesn't generate keto targets.
What makes a good app to track macros?
Not the size of its food database. Ask whether it tells you which formula produced your targets, whether those targets sit inside the AMDR, and whether logging is quick enough that you'll still be doing it a month from now. Most macro calculator apps get the arithmetic right and lose you at the third one. A calorie and nutrient tracker you open every day beats a more thorough one you delete in week two.
Do I need to hit my macros exactly?
No. Aim for the week rather than the day. Being consistently near your targets beats being occasionally exact, which is the same lesson that shows up in the calorie-tracking evidence.
Start simple, adjust as you go
Don't overcomplicate this. Set a protein target around 1.6 g/kg and hit that first, since it's the macro with the clearest evidence behind a specific number.5 Push your fibre toward 25 to 29 g a day.6 Favour unsaturated fats over saturated ones.7 Then let the rest fall where it falls inside the ranges.
Four decisions, all of them sourced. That gets you most of what a macro split has to offer, and the precision you're giving up is a rounding error next to whether you keep going.
Sources
Every figure above traces to one of these. If you find a number that doesn't match the source it claims, tell me and I'll correct it.
- Food and Agriculture Organization of the United Nations (2003). Food energy: methods of analysis and conversion factors. FAO Food and Nutrition Paper 77. Read the paper →
- Institute of Medicine (2005). Acceptable Macronutrient Distribution Ranges, in Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. The National Academies Press. Read the report →
- Westerterp KR (2004). Diet induced thermogenesis. Nutrition & Metabolism, 1:5. Read on PubMed →
- Leidy HJ, Clifton PM, Astrup A, et al. (2015). The role of protein in weight loss and maintenance. American Journal of Clinical Nutrition, 101(6):1320S-1329S. Read on PubMed →
- Morton RW, Murphy KT, McKellar SR, et al. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 52(6):376-384. Read on PubMed →
- Reynolds A, Mann J, Cummings J, Winter N, Mete E, Te Morenga L (2019). Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet, 393(10170):434-445. Read on PubMed →
- Sacks FM, Lichtenstein AH, Wu JHY, et al. (2017). Dietary fats and cardiovascular disease: a presidential advisory from the American Heart Association. Circulation, 136(3):e1-e23. Read on PubMed →
- World Health Organization. Trans fat fact sheet. Read the fact sheet →
The formulas and limits behind MyPlate's own numbers, with their citations, are on the health sources page.