We all know that being overweight has a huge impact on our health, whether by increasing the risk of heart disease and type 2 diabetes, or even contributing to 1 in 20 cancers. We may even be aware that carrying excess weight can make us feel tired, run down or breathless, as well as resulting in joint pain, digestive problems or even changes in everyday mood. But we have a problem; the majority of us are unable to identify if we and others are overweight. This is unsurprising, with 61.7% of UK adults overweight or obese, it seems we have welcomed in a new normal. So… how do you tell if you’re over the line?

What is BMI and how can I measure it?

Body Mass Index (BMI) is a nifty tool that categorises individuals as underweight, normal, overweight, obese or morbidly obese according to cut offs corroborated by the World Health Organisation. The formula above uses your weight and height to generate a BMI score; A BMI of 25 or over classes someone as overweight, and 30 or over as obese. You can calculate BMI yourself, but a much quicker and easier way can be to use an online calculator such as this one by the NHS, or to use a BMI chart such as this one by Diabetes UK.

Is BMI the whole story?

This is where things get interesting. Although being overweight contributes to ill health, the key culprit to negative health effects is excess fat. BMI however is designed only to measure excess weight, with the assumption that this weight excess is fat. In an obvious example frequent athletes may have a lot of heavy muscle, a high weight and hence an overweight BMI, despite having very low body fat and none of the associated health risks. On the flipside it is possible to have a “normal” BMI but body fat which exceeds a healthy range, often referred to as “skinny fat”.

How can I tell if I have too much fat?

Body Fat recommendations vary with age and sex – good estimates can be found here. Unfortunately there is no standardised and agreed upon definition for healthy body fat, so you may find varied guidelines in gyms or online. In general a healthy body fat for women can be between 25 and 30%, and for men between 15 and 20%, but exact ranges differ across age groups. You can measure body fat using some types of home scale, but bear in mind these are often incorrect, as accurate measurements without expensive lab equipment is difficult. You may find more accurate body fat scales in some gyms, as well as some branches of Boots the chemist.

Help, I need an easier method!

Finding a body fat measuring scale can be difficult, so a quicker measure to test for excess fat involves using your waist circumference. If a tape measure wrapped around your waist at the widest point reads above 94cm for men or 80cm for women then you may be at risk of obesity related health problems. Carrying a lot of your fat around the tummy area can also increase health risks, so this measure can be also be useful to record even if you already know you have an overweight BMI.

What Now?

If you have a normal BMI but know that you don’t do much exercise, it may be worth having a look at your waist size or body fat percentage to see if you have excess fat. If this is the case then strength building exercises are vital to increase your muscle mass and improve your body composition.

Physical activity guidelines suggest working all major muscle groups through strength exercise 2 or more days a week. Examples of strength exercises include body weight exercises such as push ups, heavy gardening such as digging and activities like yoga or weight lifting.

If all that seems a bit daunting, the NHS has a great programme called “Strength and Flex” – a no equipment needed course with free videos and resources to guide you into at home strength exercise – no expensive gym membership necessary!

Make sure to support muscle maintenance and growth by including healthy protein sources in your diet, which as well as lean meat and fish includes plant sources like legumes (e.g. peas), beans and pulses (e.g. kidney beans or chickpeas in hummus) and even wholegrains (e.g. wholemeal bread).