Understanding healthy body weight

According to the NHS BMI calculator, here are what different BMI scores mean:

• 18.4 or less is the underweight range
• 18.5 to 24.9 is the healthy weight range
• 25.0 to 29.9 is the overweight range
• 30.0 or greater is the obese range

However, the BMI calculation is just one measure of health. It isn't precise because it cannot determine the difference between muscle and fat. This means more assessments, such as waist measuring, would be required to establish a diagnosis.

Your waist size can indicate how much visceral fat is around your belly. Visceral fat, which surrounds the organs, is linked to diabetes, high cholesterol, and high blood pressure.

To measure your waist, find the midpoint between the bottom of your ribs and the top of your hips, just above your belly button. Wrap a tape measure around this point, ensuring it is snug but not tight enough to dig into your skin. Measure twice for accuracy.

Men's waist circumference

• A waist circumference of 94cm (37 inches) or less is a low risk. This is 90cm (35.4 inches)for men of African Caribbean, South Asian, Chinese and Japanese origin)
• A waist circumference of 94cm to 102cm (37 to 40 inches) is a high risk.
• A waist circumference of 102cm (40 inches) or more is a very high risk. This is greater than 90cm (35.4 inches) for men of African Caribbean, South Asian, Chinese and Japanese origin).

Women's waist circumference

• A waist circumference of 80cm (31.5 inches) or less is a low risk. 
• A waist circumference of 80cm to 88cm (31.5 to 34.6 inches) is a high risk.
• A waist circumference of 88cm (34.6 inches) or more is a very high risk. This is greater than 80cm (31.5 inches) for men of African Caribbean, South Asian, Chinese and Japanese origin).

African Caribbean, South Asian, Chinese, and Japanese people tend to carry more fat and less muscle at the same weight as white Europeans. And the risk of diabetes and heart and circulatory diseases starts to increase at a lower weight gain than for Europeans.​

Earlier, we discussed macronutrients, micronutrients, and daily requirements for adults. According to the Eatwell Guide, adults should aim for:

• 45 per cent to 65 per cent of total intake from carbohydrates
• 20 per cent to 35 per cent from fat
• 10 per cent to 35 per cent from protein

The amount of food consumed is measured in calories. The amount of calories you need is influenced by:

• Your age: children and teenagers may need more calories as they burn more energy
• Your lifestyle: active people need more calories as they burn more energy
• Your height and weight can influence your daily calorie needs
• Your hormone production, as it can affect weight gain/loss
• Your medication as it can affect weight gain/loss
• Your general health. Your specific health conditions may mean you need more or fewer calories than the usually recommended amount.

Food provides the energy our bodies need to function, much like petrol powers a car. The energy from food and drinks is measured in calories. A calorie is defined as the amount of energy required to raise the temperature of 1 gram of water by 1°C.

The type and amount of food a person should eat depends on their daily calorie needs. Different nutrients provide varying amounts of energy:

• Carbohydrates: four calories per gram
• Proteins: four calories per gram
• Fats: nine calories per gram

The amount of energy we need varies from person to person and depends on factors such as age, gender, health, and daily physical activity. The more active we are, the more energy and food we require.

It is important to eat the right amount of food to stay healthy. Eating too little or too much can lead to unhealthy weight changes and health problems.

How many calories do I need?

To determine your daily calorie needs, you first need to calculate your Basal Metabolic Rate (BMR). BMR is the number of calories your body requires to function at rest, supporting basic processes like breathing and circulation. You then add the calories needed for physical activity, from small movements like blinking to more intense actions like running for a bus.

• Calculate your BMR (male)
• Calculate your BMR (female)

Your BMR is calculated using a formula that varies based on your height, weight, age, and gender.

BMR represents the calories needed to support basic bodily functions at rest. It does not account for the extra energy required for daily activities, meaning the calories needed to live healthily will always be higher than your BMR.

You should never consume fewer calories than your BMR, as this can negatively affect body functions and lead to harmful health consequences.

To determine your daily calorie needs and understand how much food and drink to consume, you need to calculate both your BMR and the calories required for daily activities. These activities include everything from waking up in the morning to going to the gym.

Your calorie needs will vary based on your activity level. The more active you are, the more calories your body will require.

• Calculate your daily calorie intake (male)
• Calculate your daily calorie intake (female)

Calories and macronutrients

Once you determine your daily calorie needs to maintain a healthy weight, you can translate this into the types and amounts of food required. Adults should aim to consume:

• 45% to 65% of calories from carbohydrates
• 20% to 35% from fats
• 10% to 35% from proteins

Carbohydrates and proteins provide four calories per gram, while fats provide nine calories per gram. This breakdown helps guide balanced and healthy eating.

Click here to calculate your daily nutrient intake. Before calculating this, make sure you have calculated your daily calorie intake (above.)

Consuming more calories than needed can lead to weight gain and, over time, obesity. Obesity increases the risk of certain cancers, such as bowel and breast cancer, and raises the likelihood of developing serious conditions like coronary heart disease, stroke, and type 2 diabetes. Understanding the calorie content of food and drink can help you avoid consuming more calories than your body requires.

While we may think we know our eating patterns, it’s easy to overlook the details of everything we consume. Many people forget to account for snacks and drinks, which can add significant calories and contribute to weight gain. Keeping a food and drink diary can help you track your eating habits and make the changes needed to maintain a healthy, balanced diet.

A food diary is a daily record of what you eat and drink over seven consecutive days. You can write it down or use one of the many mobile apps available, which some people find more convenient. Alternatively, click here to access an online food diary form.

Research shows that people who keep a food diary are more successful in achieving their goals. This includes balancing their diet, reducing saturated fats, sugars, and ultra-processed foods, limiting caffeine to healthy levels, or cutting down on weekly alcohol intake.

Many people find it challenging to achieve and maintain a healthy weight.

In England, 25.9 per cent of adults are classified as obese, with a further 37.9 per cent considered overweight.

Often, weight loss efforts rely on popular diets promoted in the media or by celebrities, such as Atkins, Keto, or intermittent fasting. However, nutritional needs vary from person to person, meaning no single diet works for everyone. This is why nearly 95 per cent of people who follow weight loss diets fail, either by quitting too soon or regaining the lost weight—sometimes even more—within a short period.

Instead of restrictive diets, focus on understanding your eating habits and calorie intake to make sustainable changes. A food diary can help track your habits and identify areas to improve. Weight loss is about replacing unhealthy behaviours with healthy, long-lasting ones. It’s a personal process that requires time, commitment, and individual adjustments for success.

When measuring foods and counting calories, it’s easier to track nutrients for meals you prepare yourself. However, this can be more challenging with pre-packed ready-made foods. Nutritional labels on pre-packed foods provide key information to help you understand ingredients, portion sizes, and nutrients.

These labels can help you calculate calorie intake and identify healthier options. Checking the label each time you shop allows you to make informed choices and take control of your eating habits.

In the UK, all pre-packed food must display nutritional information on the back, including details about allergens, calories, saturated fats, sugars, and salt content.

Some supermarkets and food manufacturers also provide nutritional information on the front of pre-packed food using a traffic light system. This system is a quick and helpful way to compare the calories, fat, sugar, and salt content of different products at a glance.

Salt and sugar are cheap ways to make a meal taste better, but consuming too much can harm your health. Daily salt intake should be limited to less than 5g, and refined sugar should be reduced or eliminated from your diet. Processed foods and drinks often contain high levels of salt and sugar.

Foods high in salt and sugar include:

• Cheese
• Breakfast cereals
• Canned soups
• Bread, pastries, and pizzas
• Biscuits, cookies, and cakes
• Processed meats like sausages, bacon, and ham
• Sauces such as gravy, ketchup, mustard, brown sauce, and soy sauce

Excessive salt can raise blood pressure and increase the risk of cardiovascular diseases. Replace salt with spices like garlic or onion powder when cooking. High sugar consumption can lead to obesity and diabetes. Choose home-baked goods made with dried fruits instead of refined sugars, and use sweeteners in drinks to reduce sugar intake.

Here are more ideas on sugar and salt alternatives.

Snacking between meals is an unhealthy habit that can lead to weight gain. Drinks like tea and coffee with milk and sugar, sodas, and fruit juices are also high in sugar and calories. Snacking often adds extra calories without satisfying hunger. For example, half a packet of plain digestive biscuits (about seven biscuits) contains 544 calories—a quarter of a woman’s daily intake—yet provides little fullness or satisfaction, often leading to the need for a proper meal soon after.

Avoid processed snacks like crisps and biscuits.

Choose healthier options that are more filling, such as hummus, peanut butter, nuts, roasted legumes, or smashed avocado. Avoid sugary drinks like processed coffees, smoothies, and fruit juices. Instead, drink plenty of water to stay hydrated and feel fuller for longer.

Alcoholic drinks such as wine, beer, cider, and spirits are made from natural starch and sugar through fermentation and distillation, which is why they are high in calories.

Alcohol provides seven calories per gram—almost as much as fat and twice as much as carbohydrates or proteins. Additional calories may come from mixers like cola or tonic water. These calories are often referred to as 'empty calories' because they offer no nutritional value and are consumed on top of the calories your body needs.

A standard glass of wine can have up to 158 calories, while a pint of stronger lager can contain up to 222 calories—nearly 10% of the daily intake for an active adult male.

Excessive or regular alcohol consumption not only contributes to weight gain but also negatively affects overall health.

Reducing alcohol intake should be a priority when improving your diet.