Macros for a cut and a bulk: how the split is set and why carbs move first

By Robert Robinson, founder of Neato Health · September 15, 2026 · 4 min read

Once the calories are set, three numbers divide them. Here is how Neato sets protein, fat and carbs, where each rule comes from, and why the carb number is the one that moves when the plan changes.

A calorie target says how much. Macros say what. The three macronutrients, protein, fat and carbohydrate, carry all of the calories in food, at 4, 9 and 4 calories per gram, and how the day’s calories divide between them affects hunger, training and what the weight change is made of. Neato sets the split with three rules, and knowing them makes the numbers on the Food dashboard easier to trust.

Rule one: protein is a floor, set from the goal

Protein comes first because it has a job the other two cannot do: it is the raw material for muscle, and in a deficit it is what keeps muscle from being burned for fuel. The protein guide covers the evidence; the short version is that Morton’s 2018 meta-analysis found gains plateau around 1.6 grams per kilogram a day, and Neato’s default of 0.8 grams per pound sits just above that.

The weight the number is based on is your current weight or your goal weight, whichever is lower. In a cut that means protein is set for the body you are building, and does not scale absurdly for heavier people. In a bulk it grows with you. Either way, protein is set before anything else and does not move when the calorie target does.

Rule two: fat takes about 28 percent

Dietary fat has a floor too. It carries the fat-soluble vitamins, it is the raw material for hormones including testosterone and estrogen, and diets that push it very low tend to produce the hormonal disruption and the misery that Helms, Aragon and Fitschen catalog in contest-prep athletes. The Dietary Guidelines for Americans put the acceptable range at 20 to 35 percent of calories.

Neato sets fat at about 28 percent of the day’s calories, the middle of that range. On a 2,000-calorie day that is about 62 grams. It is a percentage rather than a fixed gram count, so it scales with the target; a bigger day allows more fat, a smaller day less, and it never falls out of the guideline range on either side.

Rule three: carbohydrate is the remainder

Whatever calories are left after protein and fat go to carbohydrate. It is the flexible macro because it has no comparable floor: the body can make the glucose it needs from protein, and the fiber and micronutrients in carbohydrate foods can be had at a wide range of intakes. It is also the macro that fuels hard training, which is why the remainder should not be thought of as leftover. For most people it is the largest number of the three.

This is the rule that makes the split move with the goal. When Neato raises the deficit, protein stays put and fat stays at its share, so nearly all of the cut comes out of carbohydrate. When the surplus for a bulk goes in, carbohydrate is where it goes. The carb number is the dial; the other two are the settings.

Does the ratio itself change fat loss?

Less than the diet wars suggest. Hall and Guo reviewed the controlled feeding studies in 2017, the ones where every calorie was provided and measured, and found that at equal calories and equal protein, the split between fat and carbohydrate made little difference to fat loss. Low-carbohydrate diets lose more weight in the first weeks, but it is glycogen and water, as the scale guide explains, not fat. Over months, the calories decide the fat and the protein decides the muscle. The fat-carb split mostly decides how you feel while doing it.

That last part is not trivial. Some people are hungrier on low fat, others on low carb, and the diet that is easiest to stick to is the one that works. Neato’s split is a sensible default, and the app lets you override any of the three in Goals if experience says a different balance suits you. Protein should stay at or above the default; the other two are yours to trade.

Reading the Food dashboard

The dashboard shows target, eaten and remaining for all three macros alongside calories. Two habits make it useful. Watch protein first: if the day is nearly done and protein is far behind, that is the gap to close, and it usually closes at breakfast the next day. And let carbohydrate absorb the variation: a day that runs over on carbs and under on fat, or the reverse, is a normal day. The number that has to land is calories, and the number that has to be met is protein. The rest is texture.

Neato’s guides are general wellness information built from the published research cited above. They are not a diagnosis, treatment, or medical advice, and they don’t know your history. For decisions about your health, talk to your doctor.