Optimal macros for cutting - losing body fat and getting lean.Macronutrients 101 | Science broken down
Everybody appreciates the importance of nutrition in regards to any sort of fitness goal.
If you want to lose body fat but aren’t in a calorie deficit – you’re going to get nowhere.
If you want to gain as much muscle mass as possible over a particular year, but aren’t spending the majority of your time in a calorie surplus – you’re going to struggle.
But calories in vs calories out is just the beginning of it all – the foundation on which you build upon. What about your macros?
What are macros?
Macros (macronutrients for short) refer to the three main components of your calories: Proteins, carbohydrates and fats. If you’ve already read my complete fat loss article (read the article here), you already know a bit about macros, but for completeness, let’s take it from the top.
Protein: 4 calories per gram.
Carbohydrate: 4 calories per gram.
Fat: 9 calories per gram.
Fibre generally contains 0 calories – although this is not always true as some soluble fibre contains calories (albeit, not many).
Alcohol contains roughly 7 calories per gram.
This is where your calories come from, and is the reason why not all calories are created equally – 20grams of protein and 20grams of carbs can have different implications on the body, despite both yielding 80 calories. That’s not to say calories aren’t king however, because they are, but to “enhance your results” you really want to be effectively setting up your macros.
That means you need to know how many calories to eat per day (seeing as your macros are the constituents of your calories).
Use my free calculator to determine your daily caloric needs.
Want to skip all of the chat and get your macros now? Find a comprehensive summary at the bottom of the page.
This is a quick-start guide meaning that I’m going to do my best to cut out any unnecessary mumbo-jumbo and just bring you the take home content (I like being thorough, but for a topic like this which could get extremely depth-y, the article would just become too long).
Thankfully – I’ve already written a complete article on the optimal protein intake for bulking/cutting, so I highly recommend you check that out here.
However, if you’re a bit lazy (I’m not judging you), here’s the take home points from that article:
- 1.8grams – 2.8grams per kg of lean bodyweight.
- Protein intake should be scaled up as body fat gets lower/diet gets longer (higher bodyfat = less “need” for more protein)
- Higher protein intakes promote better satiety and can help retain muscle mass.
- Be wary to not increase protein so high that carbs & fats become unecessarily low.
More comprehensive summary can be found at the bottom of the page.
There is a vast amount of support in favour of a high(er) protein diet when it comes to weight loss. The main two reasons being satiety and lean body mass retention.
I recommend protein being the first macronutrient which you set for yourself when determining your protein/fat/carb intakes. This way, you know how many calories you’re left with after consuming the adequate amount of protein.
(Remember, protein has 4 calories per gram, so 160grams of protein per day = 640 calories per day from protein.)
For those interested in purchasing a protein supplement to help you reach your daily protein goals – I highly recommend this protein from MyProtein – Good quality, extremely good value for money & many flavours available to choose from.
We’re going to keep this one very simple for this article.
Fats are essential and should never be considered a macronutrient to “eliminate”. If you are a male, this holds true to an even greater extent, as fat plays a large role in the synthesis of important sex hormones, namely testosterone. There will be more on this in a separate article but essentially, you do not want to drop your fat (and specifically, your saturated fat intake) too low, because a corresponding drop in testosterone levels is likely to occur   .
This concern regarding sex hormones still applies to women – although they could likely “get away with” a low(er) fat approach, should it be necessary. I digress.
How much fat to consume then?
Fats are similar to proteins in that, there is an adequate amount of them to consume but any amount past that point is likely not useful – and would just be consumed to cater towards individual preferences & promote adherence.
In terms of hormonal health, a higher fat approach is recommended – the problem with this is, with fat being the most calorie dense macronutrient (9calories per gram) compared to carbs and proteins (4 calories per fram), an increase in daily fat intake can seriously dampen proteins/carbs.
This can be a problem for anyone undergoing some kind of exercise regime including resistance training due to the importance of both macronutrients.
A fat intake between 20% and 30% of daily calories seems to be ideal in ensuring adequate hormonal health amongst resistance trained individuals.
But there’s one problem with this. For individuals who are getting leaner and leaner, and thus their daily caloric needs are getting lower and lower, eating 20%-30% of calories from fat may result in lowered carbohydrate/protein intake. In these instances, it may be wise to opt for a slightly lower fat intake (15%-20%) of daily calories, despite the potential implications on hormonal health.
From Eric Helms’ Evidence-based recommendations for natural bodybuilding contest preparation : “attempting to maintain resistance training performance with higher carbohydrate intakes is more effective for LBM retention than attempting to maintain testosterone levels with higher fat intakes.”
If this drop in fat intake is deemed necessary towards the later stages of a diet, to achieve further levels of bodyfat reduction, it may be possible to offset a further reduction in testosterone by increasing the proportion of fat intake coming from saturated fat.
One final thing to consider is, as protein remains pretty constant (in terms of what you require per day), the ratio of fat:carbs can be toyed around with. Nothing is extremely rigid, and your taste preferences should be considered, to help you stick to your diet. Do not underestimate how crucial this variable is – if you much prefer fatty foods, do not be afraid to opt for a higher fat, lower carb approach, as long as calories are not increased (and protein should remain pretty constant).
Let’s think of carbohydrates in the simplest of senses which is – they are our bodies preferred fuel source. It has been researched, but also intuitive to think that a reduction in carbohydrates can lend itself to a decrease in energy (particular regarding exercise and resistance training), as well as a reduction in dietary adherence through lower enjoyment of food choices.
Personally, I believe that at all times in a diet, carbohydrates should be kept as high as they can be kept, given the necessary protein and fat intake for the individual. This does not mean a “high carb diet” by any means, it simply means that carbohydrates are going to have to be reduced anyway to facilitate a calorie deficit – however within your deficit, you want to eat as many carbohydrates as you can.
The statement(s) that I’ve just made may appear controversial in light of a lot of low-carb/ketogenic diets that do prove to be very effective. Here’s 2 quick reasons that might explain some of why low-carb approaches may be effective weight loss tools:
1. Lower carbs help to rid the body of excess water and deplete glycogen, which helps weight loss in the acute sense and also allows one to look leaner during the state of depletion. This is not to be confused with additional fat loss, although it may visually seem the case.
2. Lower carbs mean, by definition, you are eating more protein/fats if your calories are still the same. As protein and fats (particularly protein) can have often have a much greater effect on satiety (hunger), it is less likely that one is going to accidentally consume extra calories/may actually consume fewer calories, thus, resulting in increased weight loss.
Note how the additional fat loss comes as a result of fewer calories consumed, not the actual lower carbohydrates – the effect is indirect.
Low-carb = better for fat loss?
“If satiety is improved with lower carb diets, and there is a lot of literature supporting a lower carb approach – why are you not recommending it?”
Context. Context is everything.
You see, the majority of the literature regarding low carb diets being superior is aimed at obese persons   , whom are in a different circumstance to somebody trying to lose excess body fat in attempt to have a lean, defined and muscular looking physique*. It is not taking in to account the importance of facilitating retentions/increases in lean muscle mass which may otherwise be lost when dieting.
*What if I am obese/significantly overweight?
When you have a lot of body fat to lose, the concern to muscle retention is far lower, simply because dieting is not as much of a stress on the body when there is such a large amount of body fat to lose.
It can also be very important in these instances to lose body fat relatively quickly, to avoid health concerns.
If this is the case, I would recommend a calorie deficit of around 25%, and not focusing too much on meticulous macronutrient ratios etc. At this stage, adherence to any kind of caloric deficit is the primary concern.
Once a calorie deficit can be maintained, opting for a slightly lower carbohydrate (and thus, higher fat/protein) than suggested below may prove to be beneficial, due to the health benefits/faster weight loss seen in the literature for obese persons opting for a lower carbohydrate approach.
Some of this can be down to the way obese persons respond to insulin (they are less insulin sensitive) .
Furthermore, a lot of these studies, when decreasing carbohydrate intake, are increasing protein intake to account for the caloric compensation.
Well we’ve already established the usefulness of an increased protein intake when restricting calories, so it is not necessarily a true direct effect of the lower carbohydrates, just rather a benefit of replacing some of your daily carbohydrates with proteins   .
So, when I say “carbohydrates should be kept as high as they can” – this is in context of the diet: Assuming that the adequate protein (quite high) and fat has already been assigned to the individual’s macros, they can now fill the rest of their calories with carbohydrates.
This way, you keep them as high as possible but, due to the nature of caloric restriction, your carbohydrate intake will likely not be that high anyway (in relative terms).
The case for higher carbs.
After providing a list of studies and logic above that pertains itself to a lower carbohydrate diet, you’re probably wondering why I’m still saying to keep carbohydrates as “high as you can”. Well, that’s because you’re after sustainable, easy fat loss – not weight loss.
We want our diet to act in a way that allows continued improvements in performance and muscle mass, or, at the very least, allows us to maintain our performance/muscle mass as best we can. A diet that does not unnecessarily lower carbohydrates past a certain threshold will allow this state to occur with far greater ease, due to the ease in which the body can utilise carbohydrates as energy.
In other words, it’s far easier to gain or maintain muscle mass when the body has energy readily available at a given moment. Carbohydrates have the potential to be very anabolic (i.e. they are very useful for building & maintaining muscle), and given resistance training’s effect on glycogen levels (it eats in to them), it would be wise to ensure adequate carbohydrate intake throughout a diet.
Remember the key to building muscle mass? Progressive overload (read the full article here) – well decreasing carbohydrates is likely to reduce performance , which can reduce your ability to progressive overload, which will result in a sub-optimal state of muscle-building.
Finally, most of us like carbs. Removing them from our diet can often make the diet unnecessarily difficult psychologically (and even physiologically), and as I will always say on this site – adherence is one of the most important factors in any diet/training plan. If you don’t enjoy your diet, you won’t succeed, so I recommend a healthy balance of all 3 macronutrients for everyone in comparison to a diet that practically eliminates an entire macronutrient.
We set proteins first, then our fats, meaning that whatever calories we have left will be filled with carbohydrates. Based on the information above, you can determine what these specific numbers are. Use the tabs below to help you get started.
Don’t ever get too fixated on being “optimal” all of the time, because the additional reward is often not even tangible. Focus on the basics, and build from there.
Summary – Your fat loss macros
Set up your macros in the following order (calories -> protein -> fats -> carbohydrates).
Click on the tabs that apply to you to work out the macros suitable for your body-type.
~25% calorie deficit.
Harsher deficits are possible at this stage due to the excess body fat:
– Less concern of muscle loss.
– Caloric intake for fat loss will be much higher due to higher bodyweight (higher BMR).
– Dieting is less stressful psycholigcally and physiologically due to ability to eat more food, plus the body’s ability to readily use bodyfat stores as they are in excess.
~20% calorie deficit.
Deficit slightly less harsh now:
– Dieting begins to become more difficult as calories get lower.
– The concern for muscle retention/gain becomes more important.
– Slightly slower fat loss will help avoid potential negative effects of prolonged dieting.
~15% calorie deficit.
Deficit is much lower now at only 15%:
– Dieting is far more difficult at this stage, both psychologically and physically.
– Muscle loss is very likely to occur if calories are dropped too low (less bodyfat stores to “feed off”).
– Slower fat loss is necessary to aid performance in the gym, maintain muscle mass, and to avoid feelings of lethargy, low sex-drive etc.
- Protein requirements should not be based off of bodyweight due to the excess levels of bodyfat.
- Can be based off of lean body mass (LBM), if individual has a good estimation of their body fat %.
1.8-2.2grams per kg of LBM will be more than sufficient.
- Alternatively, consume around 20-30% of total calories from protein.
- Protein helps promote satiety (feeling full), and so can increase this amount if desired because lowering carbs/fats when obese is much less of a concern.
(Specifics less important at this stage due to high levels of body-fat -> lower risk of muscle-loss. Calorie deficit adherence is #1)
- Protein requirements should be based off of lean body mass, and not using a percentage of daily calories (unlike with significantly overweight individuals):
- 1.8-2.4grams per kg of LBM will be more than sufficient.
- Generally scaling the protein intake up alongside fat loss/period of time dieting, to help further retain muscle & promote satiety.
- Higher protein intakes still possible, however must be wary that they do not cause fats & carbs to drop too low.
- Protein requirements can be based off of bodyweight now due to the lower bodyfat percentage.
- 1.8-2.4grams per kg of bodyweight likely sufficient, although intakes up to 2.8-3grams per kg can be rational too.
- Risk of muscle loss and feeling severly hungry is far greater at this stage, and increased protein intake can help to offset this.
- Although protein must be high, it is important not to increase protein any higher than what is necessary, as this will blunt carbs and fats which become far more important at this stage for performance and hormonal health.
- Adherence to calorie deficit is most important, fat intake largely not an issue for obese individuals (i.e. it is more of an after-thought after calories).
- There is evidence that obese persons (more insulin resistant) may benefit from a lower carbohydrate approach.
In this case, a higher fat approach may be beneficial (as a byproduct of lower carbs).
- 25-40% of calories from fats would allow for lower carb intake whilst not dropping them too low.
^Range is quite broad as preference is a huge factor – sticking to calories most important.
Upper limit (40%) can be increased even further if carbohydrates still remain high due to high caloric needs.
- Fat intake should be sufficient enough to not effect hormonal health: 20-30% of daily calories.
- At this stage, variances in fat:carb ratio are likely not too important, preference still plays a huge role.
- As long as protein and carbohydrate consumption is adequate to support training, energy etc – fat intake can be manipulated somewhat.
No need to go below the 20% of daily calories as daily calories should not be that low yet to cause a need to increase protein/carb.
- At this stage of a diet, it is more likely for hormonal health to be compromised – sticking to the 20-30% of daily calories from fat will help avoid this.
- In order to maintain necessary carbohydrate and protein consumption as calories get very low, dropping fat to 15-20% may be necessary – adequate carb/protein more important for LBM retention than fat’s impact on testosterone.
- If fat must drop to 15-20%, an increase in the proportion of saturated fats consumed may help offset the reduction in testosterone.
- Adherence to calorie deficit is most important.
- There is evidence that obese persons (more insulin resistant) may benefit from a lower carbohydrate approach.
- Choosing the higher fat intake, as well as adequate protein intake will leave you with your remaining daily calories which can be filled with carbohydrates.
- Preference massively important at this stage – carb:fat ratio should be whatever the individual can most comfortably stick to whilst maintaining the deficit.
- At this stage, Protein is set around 1.8-2.4grams per kg of bodyweight, Fat is set around 20-30% of daily calories:
- Carbohydrates constitute the remaining daily calories.
- Ratio of carb:fat is increased compared to obese persons.
- Protein likely to be increased to fight hunger and muscle loss -> this can lower carbohydrate intake even further.
- Carbohydrates can simply fill the remaining calories.
- However: If calories are very low, meaning that carbohydrates are now too low and gym performance is suffering – lowering fat to 15-20% and increasing carbohydrates can help to maintain muscle mass.
-  Sallinen J, Pakarinen A, Ahtiainen J, et al. Relationship between diet and serum anabolic hormone responses to heavy-resistance exercise in men. Int J Sports Med. 2004.
-  Hämäläinen EK, Adlercreutz H, Puska P, Pietinen P. Decrease of serum total and free testosterone during a low-fat high-fibre diet. J Steroid Biochem. 1983
-  Dorgan JF, Judd JT, Longcope C, Brown C, et al. Effects of dietary fat and fiber on plasma and urine androgens and estrogens in men: a controlled feeding study. Am J Clin Nutr. 1996
-  Eric R Helms, Alan A Aragon and Peter J Fitschen. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition. 2014
^ Recommended reading.
-  Gary D. Foster, Ph.D., Holly R. Wyatt, M.D., et al. A Randomized Trial of a Low-Carbohydrate Diet for Obesity. N Engl J Med 2003
-  Frederick F. Samaha, M.D., Nayyar Iqbal, M.D., et al. A Low-Carbohydrate as Compared with a Low-Fat Diet in Severe Obesity. N Engl J Med 2003
-  S B Sondike, Nancy Copperman, M S Jacobson. Effects of a low-carbohydrate diet on weight loss and cardiovascular risk factor in overweight adolescents.
-  Cornier MA, Donahoo WT, Pereira R et al. Insulin sensitivity determines the effectiveness of dietary macronutrient composition on weight loss in obese women. Obes Res. 2005.
-  J. L. Walberg, M. K. Leidy, D. J. Sturgill, et al. Macronutrient Content of a Hypoenergy Diet Affects Nitrogen Retention and Muscle Function in Weight Lifters. Int J Sports Med 1988
-  D K. Layman, R A. Boileau, D J. Erickson et al. A Reduced Ratio of Dietary Carbohydrate to Protein Improves Body Composition and Blood Lipid Profiles during Weight Loss in Adult Women. 2003 The American Society for Nutritional Sciences.
-  Thomas L Halton, Frank B Hu. The Effects of High Protein Diets on Thermogenesis, Satiety and Weight Loss: A Critical Review. Journal of the American College of Nutrition Volume 23, 2004 – Issue 5.
-  Leveritt, Micahel; Abernethy, Peter J. Effects of Carbohydrate Restriction on Strength Performance. Journal of Strength & Conditioning Research: February 1999