Can you lose fat and build muscle (tone up) at the same time?

Lose fat and build muscle

When your goal is to build muscle/tone up and lose weight (body fat) there’s always going to be a trade off.

Even though it’s possible to build muscle in a kcal deficit (1), if this is your primary goal then it’s more beneficial to focus on eating in a kcal surplus to bring about more noticeable changes in muscle mass, and to support your training (2). The issue here is there's a higher likelihood of fat gain.

Not so good.

On the flip side, a kcal deficit will likely see a slight drop in performance and potentially in muscle.

Again, not so good.

This is the reason why we recommend starting your plan at a maintenance set of kcals. (You can estimate this figure using our macro calculator ( By doing this, it enables you to diet on the maximum number of kcals possible where depending on your results from these 4 weeks, you can then make a choice to either enter a fat loss or muscle gain phase.

Also we know that by simply undertaking a new diet will result in better food choices, better habits (drinking more water, eating more veg, sleeping better) and better training, which will also favourably affect body composition changes, even if you're not in a large kcal deficit.

This logical approach of finding your baseline also helps you avoid any drops in performance and ensures you don't put on any unwanted weight.

This phased framework is what we do with the 90 day challenge. The first 4 weeks is about dieting on the most amount of kcals possible (why would you eat less food if you don't have to!), then based on progress we can adjust your kcals and macros accordingly. Simples.

The Box Framework

So, if your goal is to both increase muscle mass and lose body fat, maybe consider finding your true maintenance first.

If you were interested in getting more help, then book a free strategy call to see how we can help with your goals >>

Further reading:

1. An increase in lean mass whilst in a 40% energy deficit!!! -

2. Aragon, A., Schoenfeld, B., Wildman, R., Kleiner, S., VanDusseldorp, T., Taylor, L., Earnest, C., Arciero, P., Wilborn, C., Kalman, D., Stout, J., Willoughby, D., Campbell, B., Arent, S., Bannock, L., Smith-Ryan, A. and Antonio, J. (2017). International society of sports nutrition position stand: diets and body composition. Journal of the International Society of Sports Nutrition, 14 -

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