Understanding obesity and how to maintain a healthy weight

Over 60% of the UK population is either overweight or obese, as defined by the World Health Organisation (WHO) body mass index (BMI) classifications. You can calculate your BMI by dividing your weight in kilograms by the square of your height in metres. 

According to the WHO classifications, you are overweight if your BMI is between 25 and 29.9, obese if your BMI is over 30 and severely obese if your BMI is over 40. 

A BMI above 25 can, therefore, indicate that you may not be a healthy weight. However, it is important to note that your BMI alone is not necessarily enough to determine your risk of certain weight-related diseases, such as gallstones, diabetes, cardiovascular disease, stroke, cancer and high blood pressure. 

Your waist circumference is an important factor to also consider in the context of your risk for certain diseases. In men, a waist circumference of less than 94cm is ideal, while in women, it is less than 80cm.

What are the consequences of excess weight?

If your BMI and waist circumference suggest you are overweight or obese, your risk of back pain, joint pain and osteoarthritis is also raised as the extra weight places greater strain on your bones and joints. 

Excess weight also makes physical activity more difficult, eg you may easily become breathless and sweat more often and increases your risk of snoring and poor sleep. 

Excess fat tissue also increases your risk of developing heart disease, diabetes, high blood pressure, infertility, fatty liver and even certain types of cancer, such as breast, colon and uterine cancer. 

Together the effects of excess weight can reduce your physical health and quality of life, which can affect your mental health, leading to self-esteem issues and depression. 

How to safely lose excess weight

Being overweight or obese means that there is an imbalance between how much energy you consume and how much energy you expend. Safely losing weight involves gradually shifting this balance. In practice, this means reducing the number of calories you consume and engaging in more physical activity on a regular basis. 

When reducing your calorie intake, it is important to do so by changing your diet to more healthy foods and drinks. A healthy, balanced diet should include a wide variety of fresh fruits and vegetables, whole grains, lean protein and fibre. Highly processed, and high-sugar, high-salt and high-fat foods should be kept to a minimum.

When increasing your physical activity, it’s important to do so gradually to avoid injuring yourself. You should aim to eventually reach 150 minutes of moderate-intensity exercise or 75 minutes of vigorous-intensity exercise every week. Moderate exercise increases your heart rate and breathing, such that you can still talk but can’t sing. 

Your exercise should be spread out across the week. You can, therefore, break up your exercise into 10-minute sessions — especially at the start of a new exercise routine, shorter bursts of exercise can help you ease into it. 

When it comes to both your diet and your exercise routine, focus on making small, consistent changes rather than large, sudden changes. This will make it more likely that you maintain these positive changes to your lifestyle in the long term. 

Crash dieting and intensive exercise regimens can actually have a negative impact on your weight loss goals as your body goes into starvation mode. This means it starts preserving energy stores, which makes it harder to lose weight. Gradual changes give your body’s metabolism more time to adapt to avoid these effects.

Where to find weight loss support

Your GP can give you advice on how to lose weight safely and direct you to NHS resources to support you, such as the NHS weight loss app and the NHS Digital Weight Management programme. 

There are also community diabetes programmes where you can get support from a nutritionist, as well as a range of private weight loss programmes. 

Safely losing excess weight and keeping it off isn’t possible without addressing what triggers your unhealthy eating behaviours. It is, therefore, important to access appropriate support and medical therapies to help you deal with the underlying issues behind your excess weight gain.