I want to lose fat and build muscle at the same time. Are my light weights enough?

• Simultaneously losing fat and gaining muscle is called body recomposition.
• It's possible if you lift heavy weights, progressively overload, and eat in a small calorie deficit.
• Eating a high protein diet and sleeping enough will help too, a personal trainer and nutritionist said.
• Read more Working It Out here.

Dear Rachel,

I'm eating in a calorie deficit and I workout six days a week. I use a pair of 2.5 kilogram (5.5 pound) dumbbells and do upper body, lower body, core, and HIIT. My goal is body recomposition, losing fat and gaining muscle at the same time. I have a lot of body fat, think I have a slow metabolism, and am having a hard time with my protein intake. Please help!

— Struggling

Dear Struggling,

It sounds like you're frustrated, but the good news is there are some simple tweaks you can make that will help you reach your goals. 

Body recomposition, or losing fat as you build muscle, is challenging — but not impossible. Losing fat requires a calorie deficit, but gaining muscle is optimally done in a calorie surplus.

However, if you're new to lifting weights, and you do it right, it's possible to lose fat and build muscle at the same time.

"Although many people claim that you cannot do it, it is indeed possible to build muscle and lose body fat simultaneously. This process is often referred to as 'recomping,'" Ben Carpenter, a qualified master personal trainer and strength and conditioning specialist, previously told Insider.

Lift heavier weights

For body recomposition, it's really important to lift weights heavy enough to stimulate muscle growth, personal trainer Rachel Trotta told Insider. 

She recommends focusing on compound exercises like squats, deadlifts, lunges, and bench and shoulder presses as these recruit large muscles.

"Lighter weights may make you feel out of breath, but they may not be putting the stress on the muscle that's needed for growth," she said.

People often choose weights that are too light for them, and while the right weight will vary from person to person, most beginners can start with goblet squats holding at least 10 kilograms (22 pounds) and deadlift 30-40 kilograms (66-88 pounds), Trotta said.

Try and train around four days a week, ensuring you give your body time to recover between sessions, as that's when the muscles grow.

Challenge yourself to use increasingly heavy weights

To build muscle, you need to challenge yourself almost to failure (where you can't complete the rep).

Aim to do sets of eight to 12 reps, and at a weight where you feel like you could only do a couple more if you absolutely had to, Trotta said. If you feel like you could do more than four more reps after the initial eight to 12, you need a heavier weight.

Once you find the weight that feels right to you, it's important to try and gradually increase the weight, reps, or sets over time — this is called progressive overload.

If you keep doing 10 kilogram (22 pound) goblet squats, for example, it will get easier as the weeks go by.

"Even though the weight is the same, the stress on the muscle is reducing because you are getting stronger," Trotta said.

Registered nutritionist Jamie Wright recommends staying active over the course of the day to keep your non-exercise activity thermogenesis (or NEAT) up — this is all the movement you do in your life that isn't formal exercise, such as walking up stairs or cleaning.

Aim to walk at least 6,000-8,000 steps daily too, he told Insider.

Plan meals around protein

You're right that eating enough protein alongside strength training is essential for body recomposition. When I cut my body fat percentage in half, eating a high protein diet helped, and it's also helped me maintain my fat loss.

Try to eat 20-40 grams of protein every three hours or so, Trotta said. Overall each day, dietitians recommend most people aim for 0.9 grams per pound of your bodyweight, because it's satiating, aids muscle recovery, and limits muscle loss when in a calorie deficit. 

If you're struggling to eat enough protein, sit down and plan your day of eating in advance — this is what I do most of the time.

Wright recommends small tweaks like adding protein powder to oatmeal or smoothies, and getting creative with spices and seasoning rather than just eating bland, plain chicken breasts.

You're doing the right thing by eating in a calorie deficit, Wright said, but ensure your deficit isn't too big, as that would make muscle building harder.

Be patient

Body recomposition takes time, Trotta said, so try not to be frustrated by slow results.

Reducing stress and getting adequate sleep play a role in fitness and fat loss too, Wright said, so make sure you're prioritizing those as much as your workouts and diet.

If you've tried everything and still aren't making progress, consider going to see your doctor and asking for a blood test to check if there's anything else at play, Wright said.

You'll get there!

Read more Working It Out:

• I want to get back into exercise, lose weight, and get fit after a long break but I feel overwhelmed. Where should I start?
• I'm considering quitting the gym to save money. What should I look for in an online fitness program or coach for home workouts?
• My knee hurts when I squat. Should I push through the pain or rest?
• If I hit my macros and calories, does it matter what foods I eat if I want to lose fat and maintain muscle?