Can You Lose Weight And Build Muscle At The Same Time?

Welcome to the 36th episode of Vegetarian Health and Longevity from Hurry The Food Up and Sports Nutritionist James LeBaigue.

Working as a sports nutritionist, there’s a common request I get from clients.

They want to lose weight, for whatever reason. Usually it’s to tone up in some form, get rid of some excess body fat. Alongside that, they want to build muscle to look more defined. 

In their mind, the two usually come together; losing weight and building muscle. And fair enough, it’s a good goal and if they can manage that then it would be brilliant.

My answer to them isn’t necessarily what you might think, but it sets them up for success in the long run. We’ll dig into that in this episode, and talk through the strategies for you to use so that if weight loss and muscle building are your goal, you know how to do it and what you should avoid.

You can find it on YouTube below or you can listen to it here on your favourite provider.

If you missed last week’s episode about the key to unlocking morning workouts then you can listen to or read it here.

Introduction to the ‘perfect pairing’

When people talk about losing weight, they normally mean losing fat mass. This is an important distinction because it’s possible to lose weight without losing fat, and we’ll discuss this more later in the episode.

As a quick heads-up, losing weight but not losing fat is something you want to avoid, and there are ways to prevent it.

But losing fat mass is usually the goal—whether it’s from a specific area like someone’s belly or trying to tone up arms or legs, this is what people refer to when they say they want to lose weight. I’ve helped a heck of a lot of people do this now, and there are tried-and-tested methods for it.

What I usually hear alongside this, though, is that they want to build muscle as well, and this can be a bit of an issue. You see, the two are at different ends of the spectrum in terms of calorie amounts and the processes going on in your body.

In order to lose fat, you need to be in a calorie deficit, and there’s no way around this. You need your body to burn excess fatty tissue, and this only happens through consuming fewer calories than your body needs.

You need to do this day in, day out for an extended period, usually for weeks or months, depending on your goal. And it’s very common that during weight loss periods, even when you follow gold-standard principles, you will lose some muscle too.

Muscle building

But when you want to build muscle, the process is slightly different. Ideally, you want to be at calorie balance—meaning you’re consuming as many calories as your body is burning—or in a slight calorie surplus.

The reason is that you’re trying to create and build new, stronger muscle tissue, and you need to give your body the tools to do this. In this case, it’s calories.

In very simple terms, this is the problem people face. They want two outcomes that are almost polar opposites: one is a creation process, and one is a breakdown process.

Now, you might be listening to this and thinking, but I’ve heard that people have done both in the past. Isn’t it possible?

It is technically possible, but it’s really difficult, and I’m telling you this because I think honesty is the best policy.

You can lose fat and build muscle at the same time, but it’s hard to do, and not many people are disciplined enough or follow the best principles to achieve it.

The Role of a High-Protein Diet

Before we get into resistance training, we need to talk about protein. If your goal is to lose fat and build—or at least retain—muscle, a high-protein diet is non-negotiable.

Here’s why: when you’re in a calorie deficit, your body doesn’t just pull energy from fat stores. Your body needs protein to carry out its daily functions, and if you aren’t getting enough from your diet then your body goes to the next most readily available source: your muscles.

Protein is the most important dietary nutrient for maintaining muscle mass during weight loss. Eating enough protein ensures your body has the raw materials it needs to maintain its function, and suppor the muscle you already have.

The research is clear on this. A protein intake of 1.6-2.2 grams per kilogram of body weight per day has been shown to help preserve muscle mass while in a calorie deficit. If you weigh 70kg, for example, that means aiming for 112-154g of protein daily.

Another benefit of protein is its satiating effect. Protein-rich meals help you feel fuller for longer, which is a huge advantage when you’re eating fewer calories.

High-Protein Vegetarian Sources

If you’re vegetarian or just trying to incorporate more plant-based meals into your diet, it’s absolutely possible to hit your protein targets. Some excellent high-protein vegetarian options include:

• Lentils: Packed with protein and fibre, lentils are great in soups, stews, or as a base for curries.
• Chickpeas: Whether as hummus, roasted snacks, or in a salad, chickpeas are versatile and high in protein.
• Tofu and Tempeh: These soy-based products are fantastic protein sources and can be used in stir-fries, salads, or as a meat substitute.
• Quinoa: A complete protein, quinoa is perfect as a side dish or in salads.
• Low Fat Greek Yoghurt: A creamy, high-protein option for breakfasts or snacks—just watch for added sugars.
• Low Fat Cottage Cheese: High in protein and low in calories, it’s great as a snack or part of a meal

One of my favourite recipe is our healthy mac and cheese. Easy, tasty, and packs a protein punch!

Resistance Training is Non-Negotiable

The second key to achieving both goals simultaneously—and one I can’t stress enough—is resistance training.

To retain muscle during weight loss or build it while aiming to shed fat, you need to put your muscles under stress. This is the stimulus your body requires to either preserve existing muscle or encourage the creation of new tissue.

The general guideline is to perform resistance training at least three times per week. Why? Because your body adapts based on the signals you send it. A high-protein diet on its own isn’t enough. If you’re not lifting weights or using resistance bands, your body doesn’t have a reason to hold onto muscle.

Keep in mind that not all exercise qualifies as resistance training. Walking, swimming, or even high-intensity circuit training are great for cardiovascular health, but they don’t apply the kind of tension your muscles need for growth or preservation. Focus on compound movements like squats, deadlifts, push-ups, or rows—exercises that challenge multiple muscle groups at once.

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Why Being a Beginner is an Advantage

If you’re new to strength training, I’ve got some good news for you. You’re in a prime position to make rapid progress.

When you first start strength training, your body adapts quickly because the stimulus is entirely new. This is what’s often referred to as “newbie gains.”

Your muscles respond by growing faster, even if you’re in a slight calorie deficit, which is why beginners are often the ones who can achieve the elusive goal of losing fat and gaining muscle simultaneously.

Over time, these gains naturally slow down as your body becomes more efficient at managing the stress from training. But if you’re just starting out, this initial phase is where you can see some remarkable changes if you follow the principles we’re discussing.

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Consistency Over Perfection

Another critical element to consider is consistency. Too many people get hung up on trying to do everything perfectly—tracking every single calorie, hitting exact protein targets, or meticulously logging workouts.

While these things can help, the reality is that consistently following a plan, even imperfectly, is far more effective than being perfect for a week and giving up the next.

Focus on doing the basics well:

1. Eat a high-protein diet.
2. Train with resistance multiple times per week.
3. Stay in a moderate calorie deficit.

When you get those things right most of the time, you’ll see results.

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Summary

Losing weight while building muscle is possible, but it requires careful planning and discipline. Start with the basics: consume enough protein to protect your muscle, perform resistance training at least three times a week, and focus on consistency over perfection.

And if you’re just starting out with strength training, you’re in an ideal position to see progress. Make the most of that beginner phase, but don’t forget that it’s your long-term habits that matter most.

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Studies used in this podcast:

Role of Dietary Protein for the Promotion of Muscle Hypertrophy