I want to lose fat but also fuel my workouts. How much should I eat?

• Losing fat requires eating in a calorie deficit, but don't go too low under your maintenance level.
• Eating regularly, and consuming plenty of protein and fiber, will help you hold on to muscle.
• Up to 15 weeks of fat loss shouldn't drastically affect performance, a personal trainer told Insider.

Dear Rachel,

I have a fat loss goal but also really love working out for getting fitter and stronger. I know I need to be in a calorie deficit to lose fat, but I'm nervous about losing strength and my performance in workouts suffering. How do I eat the right amount to lose fat while still being able to workout hard five days a week?

— Gym Junkie

Dear Gym Junkie,

It's awesome to hear you're enjoying getting stronger and fitter. I've always found that's the best way to approach training, rather than focusing on burning calories.

Fat loss is a perfectly valid goal too, and you're right that the way to do this is through a calorie deficit created with your diet.

Rachel Butcher, personal trainer and registered nutritionist at Natural Fitness Food, told me that whether your aim is strength, endurance, fat loss, or all of the above, setting performance goals — such as doing five push-ups or running a sub-30 minute 5K — can keep you motivated and help maintain a healthy relationship with fitness.

Don't drop your calories too low

The biggest mistake people make in your situation is dropping calories too low, according to Butcher and Briana Siegert, certified personal trainer and nutrition coach at CrossFit Kinesis.

This leads to energy dips and poor recovery, Siegert said. It can also result in malnutrition, lethargy, tiredness, constipation, headaches and dizziness, cramps, dry mouth, and hair thinning or loss, dietitian Tai Ibitoye previously told Insider.

Butcher recommends aiming to eat at 15% below your maintenance calories, which you can estimate with an online calculator.

"This will see you progress without your workouts suffering and also allowing you the food you enjoy," she said.

I try to listen to my body when in a fat loss phase — if my workouts all feel like a complete struggle, I'll try upping my calories slightly (perhaps in the form of a pre-workout snack) to see if that makes a difference without halting my progress.

I know I'm probably not going to be smashing PBs every week due to having less energy, but that doesn't mean I won't make any progress.

Eating regularly, ideally every three hours, can help with fat loss too, Butcher said.

"Try to make sure you're not letting hours pass by without eating when you are in a deficit or if your energy expenditure has increased, because as soon as that hunger hits, it can be a struggle," she said.

I've always found that avoiding getting ravenous makes it easier to stay on track and make nourishing food choices. If you can, prepping meals in advance can be really handy.

Eat lots of protein and fiber

For fat loss, being in a calorie deficit is king, but it isn't all that matters — the make-up of what you're eating is important too.

Ensure you're eating a balanced diet that doesn't neglect carbs or fats, but especially prioritize protein and fiber, Butcher said.

"Protein and fiber are satiating (keep you fuller longer) so your calorie deficit will be easier to adhere to — as well as the added health benefits in terms of protein preserving lean tissue (muscle) and fiber contributing towards gut health," she said.

Our bodies are all different so respond better to different ratios of protein, carbs, and fats but eating a high protein diet has helped me hit my fitness and fat loss goals.

If you're lifting weights, eating enough protein, and not in a drastic calorie deficit, you'll stand your best chance of holding on to muscle while losing fat, Siegert said.

It worked for me when I reduced my body fat percentage from 30% to 17%.

A short-term deficit shouldn't affect your performance too much

Assuming you're lifting weights and exercising for no more than about 60-90 minutes five days a week, you shouldn't experience much of a performance decrease from a short-term calorie deficit, Siegert said.

"For most people, if we approach a deficit correctly and have spent plenty of time in maintenance and building muscle, a short-term deficit shouldn't impact your strength and recovery much," she said.

However, you don't want to be in a fat loss phase for more than 12-15 weeks at a time, a couple of times a year, Siegert said. Being in a calorie deficit can lead to mental as well as physical fatigue, which is why some fitness experts recommend diet breaks.

"Remember, it's short-term for a long-term benefit," she said.

Track progress with photos

Track your progress both in the gym and aesthetically — don't rely on the scale, though, as weight can fluctuate for lots of reasons.

I have a healthy relationship with the scale and see the number just as data, so actually like weighing myself every day and then taking a weekly average, but you might find a monthly weigh-in, or no weighing at all, suits you best.

Butcher recommends taking pictures every week, from the front, side, and back, ideally at the same time of day, in the same clothes, in the same place, to ensure consistency and a fair comparison.

You got this!

Wishing you well,

Rachel

As a senior health reporter at Insider and a self-described fitness fanatic with an Association for Nutrition-certified nutrition course under her belt, Rachel Hosie is immersed in the wellness scene and here to answer all your burning questions. Whether you're struggling to find the motivation to go for a run, confused about light versus heavy weights, or unsure whether you should be worried about how much sugar is in a mango, Rachel is here to give you the no-nonsense answers and advice you need, with strictly no fad diets in sight.

Rachel has a wealth of experience covering fitness, nutrition, and wellness, and she has the hottest experts at her fingertips. She regularly speaks to some of the world's most knowledgeable and renowned personal trainers, dietitians, and coaches, ensuring she's always up to date with the latest science-backed facts you need to know to live your happiest and healthiest life.

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