BMI & Measuring Guide

BMI is an abbreviation for Body Mass Index and is used to determine if a person is underweight, overweight or within their healthy weight range. BMI works by calculating a simple ratio of weight to height that determines if your weight is healthy and is a means of assessing the risk in those who are overweight or obese. (see below Ethnicity)

• BMI below 18.5 - You are classified as underweight for your height and you should not be losing weight
• BMI higher than 25 - You are classified as being overweight for your height and need to lose weight
• BMI more than 30 - You are classified as obese for your height and need to lose weight
• BMI above 40 - You are classified as very obese for your height and need to lose weight

BMI is a helpful guide for most people over 18, but it is not perfect and does not work for some groups of people, for example:

• Adults with a very athletic build (professional athletes) could show as overweight. This is because muscle weighs more than fat, and BMI doesn’t take this into account.
• If you’re pregnant/breastfeeding, BMI doesn’t apply. You should seek advice from your doctor or midwife on what a healthy weight is.
• If you’re of Black African, African Caribbean, South Asian, Chinese, Middle Eastern and mixed family origin, your risk of chronic health conditions is greater at a lower BMI than in the white population. Risk begins to increase at a BMI of 23, and people with a BMI of 27.5 will be at high risk.

Your ethnic group can also affect your risk of some health conditions. For example, adults of Asian origin may have a higher risk of health problems at BMI levels below 25.

Lower BMI thresholds should be applied to people from black and minority ethnic (BME) groups. Recommendations from the National Institute of Health and Care Excellence (NICE) state the BMI measurement system may be “applied wrongly” to BMEs groups. For the BME population a body mass index (BMI) of 23, not 25, should be the optimal score for those with diabetes.

BME adults with a:

• BMI of 23 or more are at increased risk
• BMI of 27.5 or more are at high risk

Black, Asian and other minority ethnic groups (BMEs) have a higher risk of developing some chronic conditions, such as type 2 diabetes and in the UK alone people of black African or Caribbean descent are three times more likely to develop type 2 diabetes than the white population. Type 2 diabetes is also more common among Chinese people and people from all of these groups are more at risk of stroke.

In a study, researchers used a technique called meta-analysis to determine which combination of the various anthropometric measures (height, weight, waist etc) work best for predicting weight-related health problems such as type 2 diabetes, hypertension and heart disease. A total of 31 studies were included in the analysis involving more than 300,000 adults in various ethnic groups. Although waist measurement alone was determined a good predictor of outcomes (better than BMI), the waist/hip ratio was significantly better than waist measurement alone or BMI.

Create your Account with us and visit our Weight Loss Centre Measurement Tracker to determine your Waist to Hip Ratio

Whatever your nationality, keep your waist/hip ratio below 0.8

The original BMI Calculator was invented in the 19th Century. Unfortunately these days it is not always a true reflection of ones body fat, for example an athlete will have a larger portion of muscle. Most men carry greater muscle than women and will therefore weigh more on their scales which could indicate a higher BMI figure and possibly the need to lose weight, however their measurements may determine they are of a healthy weight.

At KeeDiet® alongside calculating your BMI we also recommend you determine your Hip to Waist ratio figure and Waist Measurement discussed below to ascertain your need for weight loss and set individual goals. As the BMI method is used by most Doctors to assess a patients need for weight loss, we also use this method to provide an online selection of weight loss plans you may wish to consider.

Waist circumference is now an important factor in weight and body-fat assessment. This is because total body fat is no longer seen as the key indicator of weight-related health problems.

Fat distribution is just as important. For example, body fat that accumulates around the waist and stomach area (abdominal fat) poses a greater health risk than fat stored in the lower half of the body.

Unlike subcutaneous fat which primarily resides directly under the skin, there is a much more dangerous type of fat to be aware of - visceral fat. This type of fat hides around the nooks and crannies deep within your abdomen and creates a cellulite swamp of fatty tissue covering organs and clotting arteries, unfortunately its harder to get rid of than subcutaneous fat but harder doesn’t mean impossible. Reducing your weight, opting for healthy foods, stopping smoking, reducing stress and increasing exercise will all help.

Undoubtedly you’ve heard the terms “pot belly” and “beer belly”. This is visceral fat that has taken up residence in the abdominal cavity, especially around the liver and can cause quite a protuberance if ignored.

Sedentary lifestyles and unhealthy diets are the main culprits for this type of fat overload, getting rid of visceral fat and maintaining a balanced diet along with regular exercise is your ticket to a longer, slimmer and healthier life!

Measuring your waist is a good way to check you're not carrying too much fat around your stomach. You can have a healthy BMI and still have excess tummy fat – meaning you're still at risk of developing these diseases.

• Find the bottom of your ribs and the top of your hips
• Wrap a tape measure around your waist, midway between these two points
• Breathe out naturally before taking the measurement
• Regardless of your height or BMI, you should try to lose weight if your waist is classified higher than below