Nutrition for Fat Loss & Muscle Retention

By November 25, 2015 April 22nd, 2019 No Comments

This article is written in the context of a weight trained male or female with a decent amount of muscle mass, trying to lose fat.

I felt this topic was worth writing about as I see countless people thinking that they have to make drastic dietary changes in order to see results. This often involves adoption of an extremist style diet such as paleo, keto, 0 sugar, or some other diet that involves a list of foods which you can and can’t eat. While these types of diet can and do work, for the short term, they are often unsustainable and so make long term progress difficult.


I do NOT advocate separating foods under “acceptable” and “unacceptable” labels like this!

Exclusion style diets are especially difficult to make continued progress with if quantitative (countable) calorie and macronutrient goals aren’t present. Why this is important is because energy and macronutrient content of a diet are the most important factors for weight change and body composition, NOT eating a select bunch of foods, or certain foods at certain times. This means tracking calorie and/or macronutrients (carbs,fats,protein) is important for continued progress. This article is not about arguing fundamental concepts of nutrition, though. I would advise everyone to watch the entirety of the Eric Helms’ Nutritional Pyramid series on Youtube if you haven’t already, it will inform or refresh you about what factors of a diet are worth paying attention to.

What Do I Recommend?

Firstly, before you attempt to lose weight, start to track every food you eat in a free online database such as Myfitnesspal. Do this for a week and average the data. This is in an attempt to gauge what your diet is made up from on average in terms of calories, carbs, fat, protein, and fibre.MFPforwebsitearticle

The same week, weigh yourself at the same time of day (at least 3x per week but preferably every day) in the same conditions. Ideally in the morning after visiting the bathroom and in the same clothes/naked. This will give you a base weight to work from. Keep your caloric  and macronutrient intake similar for the week following this, and keep weighing yourself. Now, average week 1 weight and week 2 body weight and compare them. Over these two weeks keep activity & training consistent (ie don’t suddenly increase cardio by 2x during the 2nd week). You now should have some rough data about what a certain caloric intake does to your body weight.

For fat loss periods while maximising muscle retention, weight loss should be kept within ~0.5-1.0% of total body weight per week. More than this and you risk losing too much muscle, and a slower rate than this means you can probably get away with more fat loss without sacrificing much muscle. Now, in terms of macronutrient content of the diet, shoot for around 1.8-2.7g/kg of protein/day (1). The lower end of this range is applicable to most people. The upper range of this becomes more applicable when you are extremely lean, and are losing weight quickly (to maximise muscle retention). Fibre should be around 10-15g per 1000 calories consumed, which usually falls into 25-40g/fibre day. Carbs and fats can be whatever you prefer (within total calories). There can be arguments made for dropping one or the other more. Higher carb may help to spare performance while in an energy deficit and therefore preserve muscle, and higher fat will help with satiety (feeling of fullness) and so might make the weight loss phase easier. Your intake of one or both of these macronutrients will very likely need to drop throughout the weight loss phase, so drop whatever you prefer but keep fat at least 30-50g/day minimum for health reasons.


The food you eat doesn’t matter, it is the total caloric, macronutrient, fibre, and micronutrient intake at the end of the day that is important.


track your cardiovascular exercise as well as your nutrition. The most replicable way to do this is to use a cardio machine and have a set goal per week of how many calories you want to burn through cardio. The calories burnt on these machines is not always accurate with what the machine says, but it’s usually consistent which is what matters. This makes tracking weekly cardio quantifiable, and you can adjust calories burnt per week through cardio upwards or downwards depending on what weight loss is doing. Do cardio post training or on rest days, low to moderate intensity is usually what I advocate so training is not affected. High intensity cardio can be useful too but space it away from leg training days. Remember cardio is this context is just a tool for expending more calories. Different forms of cardio don’t offer special magic fat burning properties over the other. You don’t have to do cardio, but it allows you to eat more and lose the same amount of weight compared to if you didn’t do it at all.

Track body weight changes with a graph. When your weight loss stalls (weight loss <0.5% of total BW each week for two consecutive weeks), add more cardio for example 500kcal/week extra, or reduce calories by another 100-200 through carb and or fat reductions.



Weight gain rather than loss, but an example of how weight should be tracked over time so accurate macronutrient changes can be made.

Hopefully you have a good grasp of how to effectively lose weight and remain healthy. Eat what you want within reason, hit suitable macronutrient and fibre goals, and eat 5 serves of fruit/veg day and that’s 95% of the dietary picture you need to worry about.

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  • (1) Murphy, C. H., Hector, A. J., & Phillips, S. M. (2014). Considerations for protein intake in managing weight loss in athletes. European journal of sport science, (ahead-of- print), 1-8.