Macronutrient Calculator

Six diets in a dropdown

This tool asks you one question its siblings do not. Not how much you want to lose, not what percentage split you fancy, but which named diet you want to follow. High Carb, DASH, Moderate, Zone, Low Carb, Keto. Pick one and it works out your daily calories and hands you the grams.

Which is convenient, and also slightly strange when you look closely. Those six names are not six versions of the same thing. One of them is a blood pressure treatment from a government-funded clinical trial. One is from a bestselling paperback. One is a hundred-year-old epilepsy prescription. They have ended up side by side in a dropdown as though they were flavours of the same product, and they are not.

So this page is a tour of what you are actually choosing between, because the names tell you almost nothing and the numbers tell you a lot.

DASH is the odd one out

Five of these options come from the world of physique and dieting. One does not, and it is worth knowing which.

DASH stands for Dietary Approaches to Stop Hypertension. It was not invented by an author or a coach. It came out of a multicentre randomised controlled feeding trial funded by the US National Heart, Lung, and Blood Institute, published in 1997. Four hundred and fifty-nine adults were fed, for eight weeks, on one of three carefully constructed diets, with the food supplied to them rather than left to chance. The diet rich in fruit, vegetables and low-fat dairy, and reduced in saturated and total fat, dropped blood pressure by roughly 5.5 mmHg systolic and 3 mmHg diastolic compared with the control.

Now the detail that makes DASH genuinely remarkable, and which is easy to miss on a page like this one.

Body weight was held constant for the entire trial. So was sodium. So was physical activity. The researchers deliberately fed people enough to stop them losing weight, precisely so that nobody could claim the blood pressure improvement was just weight loss in disguise. And the blood pressure fell anyway.

Sit with what that means, given where you are reading it. The one option in this dropdown with a proper randomised trial behind it is the one whose famous result was achieved by people who did not lose a single pound. DASH is not a weight-loss diet. It is a pattern of eating that changes your cardiovascular numbers on its own merits. It happens to be built out of food that tends to fill you up, which is why it also does respectably for weight and why it keeps getting ranked at the top of best-diet lists. But that is a side effect of its design, not the purpose.

If your reason for being here has anything to do with blood pressure, this is the option with the evidence. If it does not, DASH is still the most conservative, least fashionable and best-supported thing on the list, which is not the worst recommendation a diet ever had.

The Zone, and where 40/30/30 came from

Next to DASH sits the Zone Diet, and the contrast in provenance is instructive.

Forty percent carbohydrate, thirty percent protein, thirty percent fat. It is a memorable ratio, which is part of why it stuck. It comes from a 1995 book by Barry Sears called The Zone, which sold enormously and argued that holding that particular balance at every meal keeps your hormones in a favourable band.

Here is the honest position. The ratio is not dangerous and plenty of people have eaten happily inside it for years. It nudges protein up and carbohydrate down from a typical Western diet, which is a reasonable direction of travel for a lot of people. What it does not have is a randomised controlled feeding trial with 459 people and its own acronym. It has a book, a following, and a tidy number. That is a different kind of foundation from the one two options above it, and you deserve to know which you are standing on.

The same broadly goes for High Carb, Moderate and Low Carb. They are not branded programmes so much as descriptive positions on a slider, and they are fine as starting points.

Only two of the six sit inside official guidance

Here is something you can check yourself, and it reframes the whole dropdown.

The Institute of Medicine publishes Acceptable Macronutrient Distribution Ranges for healthy adults: carbohydrate 45 to 65 percent of energy, fat 20 to 35 percent, protein 10 to 35 percent. Hold each of these six presets up against all three ranges and this is what happens:

Two out of six. The two that pass are the two nobody writes books about.

Do not over-read this. Falling outside the ranges is not a health warning, and the ranges themselves are wide precisely because the evidence would not support anything narrower. Our Macro Calculator goes into what those ranges are and why they are so broad. But it is worth noticing that four of the six things offered here as diets involve deliberately stepping outside the official envelope, and that the dropdown does not mention it. Now you know, and you can step outside on purpose rather than by accident.

The keto option in particular deserves more than a line in a menu. At 10 percent carbohydrate it is a metabolic intervention, not a rebalancing, and our Keto Calculator treats it properly.

How a percentage becomes a plate

The arithmetic is simple enough to follow. The tool finds your resting burn with the Mifflin-St Jeor equation, multiplies by your activity factor to get your daily calories, splits those calories by the percentages of your chosen diet, then converts each slice into grams. Carbohydrate and protein carry 4 calories per gram; fat carries 9.

Take a 35 year old woman, 165 cm, 68 kg, exercising 3 to 5 times a week. Her resting burn works out at about 1,375 calories, and with the moderate activity factor of 1.55 her daily total is roughly 2,132. Choose the Moderate balance, at 50 percent carbohydrate, 25 percent protein and 25 percent fat:

Notice the last column. Protein and fat have identical shares of her calories, yet the protein number is more than double the fat number in grams. Nothing has gone wrong. Fat simply carries more than twice the energy per gram, so an equal slice of calories buys you less than half as much of it by weight. That gap trips people up constantly, and our Macros Calculator pulls it apart in detail.

One thing this tool does not do: it has no goal setting. Every number here is pitched at maintaining your current weight. If you want a split aimed at losing or gaining, our Macros Calculator combines the two.

Questions people ask

Which of the six should I pick?

If you have a blood pressure reason, DASH, because it is the only one here with a randomised trial behind it. Otherwise pick the one whose food you would actually enjoy eating in six months. The split matters far less than sticking to it.

Will DASH help me lose weight?

It can, but not because of its macro ratio. Its landmark trial deliberately held weight constant. It tends to help because it is built from filling, unprocessed food, not because 55/18/27 is a magic combination.

Why are these numbers only for maintaining my weight?

Because this tool does not ask for a goal. It answers the question "what would this diet look like for me", not "how do I lose weight on it". Pair it with our Calorie Deficit Calculator if you want a target to eat to.

Can I switch between them?

Yes, and the calculator makes that easy. But changing your split every few weeks is a good way to never find out whether any of them works for you. Pick one and give it a couple of months.

References

Where the figures come from. The DASH trial, including the fact that body weight, sodium and activity were held constant throughout, is Appel and colleagues' 1997 study in the New England Journal of Medicine; the eating plan's macronutrient profile of 55 percent carbohydrate, 18 percent protein and 27 percent fat is as published by the National Heart, Lung, and Blood Institute. The Acceptable Macronutrient Distribution Ranges are from the Institute of Medicine. The Zone ratio comes from Barry Sears' 1995 book. The resting equation the tool runs is Mifflin-St Jeor.

1. Campbell AP. DASH eating plan: an eating pattern for diabetes management. Diabetes Spectrum. 2017;30(2):76-81. https://pmc.ncbi.nlm.nih.gov/articles/PMC5439361/
2. Svetkey LP, Simons-Morton D, Vollmer WM, et al. Effects of dietary patterns on blood pressure: subgroup analysis of the DASH randomized clinical trial. Archives of Internal Medicine. 1999;159(3):285-293. https://pubmed.ncbi.nlm.nih.gov/9989541/
3. MedlinePlus. High blood pressure and diet. US National Library of Medicine. https://medlineplus.gov/ency/article/007483.htm
4. National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Energy. Washington DC: The National Academies Press. https://www.ncbi.nlm.nih.gov/books/NBK591020/
5. Sears B, Lawren B. The Zone: A Dietary Road Map. New York: ReganBooks; 1995.
6. Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition. 1990;51(2):241-247. https://doi.org/10.1093/ajcn/51.2.241