A study has shown that in the UK you are more likely to be obese than underweight.

The study conducted by The Imperial College London compared the BMI (body mass index) of around 20 million men and women over the last 30 years around the globe and found that obesity has more than doubled in women and tripled in men.

The study published in The Lancet focused on 186 countries worldwide and found that obesity has grown from 105 million in 1975 to 641 million in 2014.

Over the same time, the proportion of underweight people fell from 14 percent to 9 percent of men and from 15 percent to 10 percent of women, according to the study. Despite this starvation is still a serious threat in some regions.

Based on these findings, the researchers estimated that in nine years, a fifth of all adults globally and 40% of American adults will be obese.

To qualify as obese you need a BMI score of over 30, whilst a score of under 18.5 is classed as underweight.

The author of the study concluded the findings by warning: “To avoid an epidemic of severe obesity, the next step must be to implement these policies, and to systematically assess their effect.”

How to measure BMI

Keeping track of BMI can help you avoid obesity

BMI is the recognised method of measuring whether a person's weight is right for their height.

BMI is measured by calculating a person's weight in kilograms divided by the square of the person's height in metres (kg/m2).


A score of less than 18.5


A score of 18.5- 24.9


A score of 25 - 29.9


A score of 30 or above

Overweight BMI

People with an overweight BMI are more likely to develop health problems such as:

  • Heart disease
  • Stroke
  • Type 2 diabetes
  • Some types of cancer
  • High blood pressure
  • Kidney disease

Regular exercise and a healthy diet can help to reduce BMI and eliminate these risks.

Underweight BMI

People who are underweight are also at risk of health issues such as:

  • Brittle bones (Osteoporosis)
  • Absent periods in women
  • Iron deficiency (Amnesia)

Weight lifting and gradual weight gain can help to target these issues.

BMI Accuracy

Healthcare professionals take multiple factors into consideration when assessing weight, as BMI alone does not take into account muscle. Muscle weighs more than fat and therefore a person who has a lot of muscle mass may have an overweight BMI, despite having a healthy level of body-fat. For example, athletes, heavyweight boxers and weightlifters are often classed with overweight BMI due to the density of their muscle mass.

Another way to measure fat levels is to use the hip to measure waist to hip ratio seen here.

How to measure BMI

As mentioned above BMI is measured by calculating weight in kilograms divided by the person's height in metres squared. Whilst this can be calculated manually, there are also a variety of tools which can track progress and measure BMI.

Smart scales

Smart scales monitor your BMI as well as providing an in depth analysis of your body composition.

Garmin Index Smart Scale

The Garmin Index Smart Scale aims to create a picture of health for the user, creating a full circle of wellness and weight management which can be combined with their fitness wearables. The scale tracks weight, body mass index, body fat and muscle mass.

A full review of this product will follow.

Omron Scales

The Omron scales provide insight into your body and visceral fat, skeletal muscle level, BMI and resting metabolism. It is a clinically validated scale and classified as a medical device.

See: http://www.omron-healthcare.com/en-gb/products/weightmanagement#

Visit your GP

Your GP will be able to measure your BMI as well as assess what health benefits or implications may come from your score, as well as testing for other issues and offering treatment and support.

Online calculator

The NHS offer this quick and simple BMI calculator, along with plenty of other advice. You will need to know your accurate height and weight for the most precise results.


Is BMI useful?

Whilst BMI is useful, it can only tell if you’re carrying too much weight. The BMI can't tell the difference between excess fat, muscle, or bone.

The NHS states that adult BMI does not take into account age, gender or muscle mass. This means that:

  • very muscular adults and athletes may be classed "overweight" or "obese" even though their body fat is low   
  • adults who lose muscle as they get older may fall in the "healthy weight" range even though they may be carrying excess fat

However, the BMI is a relatively straightforward and convenient method of assessing someone's weight.

  • Posted byVictoria Gardner /
  • Clean Eating