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Obesity and Weight Gain

Dr Roger Henderson
Reviewed by Dr Roger HendersonReviewed on 13.10.2023 | 4 minutes read

In the simplest of terms, if the calories you eat exceed the calories you burn off, you will put on weight. The bulk of calories are sugary and fatty foods, especially in those that are highly processed or in takeaways – those foods designed to make us want more.

Doctors have a scale to classify whether your weight is healthy, underweight or overweight, and it’s based on your body mass index (BMI), which takes into account your height and weight (kilograms per metres squared).

You have a healthy BMI if it’s between 18.5 to 24, and underweight if less than 18.5. A BMI of 25 to 29 is termed overweight, 30 to 39 is obese, and over 40 is classed as very obese.

Obesity is a growing problem, currently affecting one in four adults in the UK, and it can have serious implications for your health, including increased risk of breast and bowel cancer, Type 2 diabetes, heart disease, stroke, and disability from pressure on your bones and joints.

What does obesity mean?

Obesity is a growing problem, currently affecting one in four adults in the UK, and it can have serious implications for your health, including increased risk of breast and bowel cancer, Type 2 diabetes, heart disease and stroke.

BMI gives an indication of obesity, but a diagnosis is made based on other factors such as waist circumference. Men with a waist size of 94cm or women with a waist of more than 80cm put their health at risk.

As muscle weighs more than fat, bodybuilders and others with a high proportion of muscle mass may appear to have an unhealthy BMI, but this needs further consideration as they may have a low-fat content. You would expect it to only push them into the overweight category, rather than obese.

Could there be a medical reason behind my weight gain?

If you have gained considerable weight over a few weeks or months without changing your diet, portion size or activity level, consider whether you have any other symptoms. Hypothyroidism, or an underactive thyroid gland, is a common condition where your metabolism slows down – you should visit your doctor for a blood test if you feel cold all the time or you’re lacking in energy and sleeping more than usual. Medication can help return your thyroid function to normal.

Pregnancy is another obvious cause for weight gain – if this could be you, take a pregnancy test to check.

Certain ethnicities have a tendency to conserve calories from food – this isn’t a medical cause, just genetics. Unfortunately, it means that you (and your children) need to be more careful about food choices, portion sizes and getting enough exercise to burn calories off.

When should I see my doctor?

If you have any concerns about the medical conditions above you should book a routine appointment with your doctor. If you have no other symptoms, you can try simple measures to lose weight at home. you should try to reduce your intake of calories by making healthy food choices and reducing portion sizes and snacks. Drinks can add substantial calories – fizzy drinks, processed fruit juices and alcohol are all packed with calories, so cut back on these if this applies to you.

Unfortunately, there is no magic pill, single food group or radical smoothie to shortcut weight loss – it requires hard work and planning from you. Weight loss programmes can help to guide your choices and provide a supportive group to cheer you on.

Some areas have exercise on prescription available, where your doctor can refer you to the local gym or swimming pool for a number of sessions. You may also be a candidate for certain medication that makes it harder to absorb the fat from your diet, called Orlistat, but you need to keep losing weight to stay on this. Weight loss surgery (bariatric surgery) may be offered under certain criteria – usually with a BMI of over 40 – and it requires a great deal of commitment before and after surgery.

Sometimes, it can feel an uphill struggle to lose weight and add to feelings of low self-esteem and confidence. If you are already feeling depressed, it can be hard to find the motivation to address your weight, and easy to comfort eat, which adds to the pounds. If your mood is low, see your doctor to discuss how you can best tackle this – set one goal at a time to put yourself in a position to succeed.

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Dr Roger Henderson
Reviewed by Dr Roger Henderson
Reviewed on 13.10.2023