How to gain weight and muscle safely

Our bodies naturally change over time. Your weight and muscle mass can shift because of illness, lifestyle changes or even something as simple as a change in appetite – and that’s completely normal. Looking after a healthy weight and muscle mass plays an important role in everyday life, from how strong you feel to how much energy you have. You might be looking to gain weight or build muscle to support your health, your confidence or to simply feel more like yourself again.

Before you begin your weight-gain journey, it’s helpful to understand where you’re starting from. Checking your current weight can give you a clearer picture, but remember – a healthy weight looks different for everyone. Factors like your height, age and overall health all play a part. One simple way to get an idea of where you sit is by using our BMI calculator, which shows your body mass index (BMI). In general, a BMI below 18.5 may suggest that your weight is on the lower side.¹ That said, BMI doesn’t tell the whole story. It doesn’t take muscle mass into account – and because muscle weighs more than fat, people with more muscle may appear to fall into a higher BMI category even if they have low body fat. BMI should therefore be considered alongside other factors, including strength, energy levels and overall wellbeing rather than used in isolation.

Many different factors can influence your weight and muscle mass and often it’s not just one thing. For some people, a combination of these factors can make gaining weight or building muscle feel challenging, while others may find it harder to lose weight instead. Either way, it’s important to remember that healthy change takes time. Your body, your lifestyle and even your circumstances all play a role.² These can include:

Whether your goal is health, confidence or appearance, building muscle comes with a whole range of benefits. Increasing muscle mass contributes to overall metabolic function, as muscle tissue is metabolically active and plays a role in how your body uses energy.⁵ Muscle gain can help strengthen your muscles, bones and tendons, which can help reduce the risk of injury and make things like opening a stubborn jar easier. Building strength, especially in your core, can also improve your balance and coordination. Over time, this can help you feel more stable, confident and capable in how you move through everyday life.⁵

Here are four lifestyle changes you can make to encourage weight gain in a safe and healthy way:

While it might sound simple, what you eat makes a big difference when it comes to healthy, sustainable weight gain. A balanced, nourishing diet that provides enough calories for your height, age and activity level can help you reach a healthy weight and supports muscle gain when combined with resistance exercise. As a general guide, the average adult woman needs around 2,000 calories a day to maintain weight, while the average adult man needs about 2,500 calories.⁶

As Molly explains, “Healthy weight gain is most effective when calorie increases come from nutrient-dense foods (think fish, chicken, eggs, turkey, tofu, oats, rice, nuts, fruit and vegetables) rather than highly processed foods that are high in saturated fat and added sugars – and may contribute excess energy without the same nutritional value.”^7,8,9

Gaining weight and building muscle in a healthy way is a gradual journey, but with the right combination of diet, exercise and consistency, it’s achievable. Alongside your training and nutrition plan, don’t overlook the impact of proper hydration and sustained energy on your results – that’s why we asked an expert on the link between hydration and sports performance. You can also discover helpful support for busy training days in our top products to support your energy. Before starting any weight or muscle programme, it’s important to check in with your doctor. They can help ensure your plan is safe and provide advice tailored to your body and goals.

Disclaimer – This article provides informational advice and is not a substitute for medical care. Curated by experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.