For weight loss, this can be useful for a number of reasons, not least because it can be very motivational to see inches, as well as pounds, drop off, but for health, there is another very important reason to look at this measurement.
More than 60 years ago, the French physician Jean Vague observed that people with larger waists had a higher risk of premature cardiovascular disease and death than people who had trimmer waists or carried more of their weight around their hips and thighs. (1) Decades later, we now have long-term follow-up studies that confirm what he suspected – that so-called “abdominal obesity” is strongly associated with worse health outcomes and can result in an increased risk of type 2 diabetes, cardiovascular disease and cancer, even after controlling for weight and body mass index (BMI) (2,3,4).
As carrying your weight around your waist or abdomen is considered to be a higher risk, international health organizations have given guidelines on what is a healthy waist circumference and these numbers are given in the table below. The numbers we use at Future Fit are in line with the NHS and we also use numbers from the International Diabetes Federation for the different ethnic groups.
| Organization | Measurement used | Definition of abdominal obesity |
| American Heart Association, National Heart, Lung and Blood Institute (5) | Waist circumference | Women: > 88 cm (35 inches), Men: > 102 cm (40 inches) |
| International Diabetes Federation (6) | Waist circumference | Women: > 80 cm (31.5 inches), Men: > 90 cm (35.5 inches) Different cut-points for different ethnic groups |
| World Health Organization (7) | Waist-to-hip ratio | Women: > 0.85, Men: > 0.9 |
| NHS / NICE (8) | Waist Circumference | Some Risk
94cm (37ins) men 80cm (30.5ins) women High Risk 102cm (40ins) men 88cm (34ins) women |
About 90% of body fat is stored in a layer just beneath the skin and is called subcutaneous fat. The remaining 10% is found beneath the abdominal wall and in the spaces surrounding the liver, intestines and other organs. This is known as visceral fat and although it only makes up a small percentage of total body fat, it is the main reason why gaining weight here causes a higher risk of diabetes, cardiovascular disease and some cancers.
Up until the mid-1990s, researchers believed that the main function of fat cells was to store energy and it is only since then that scientists have discovered that fat cells are in fact biologically active endocrine glands, secreting a variety of hormones and other molecules that have far-reaching and diverse effects on the body.
The precise mechanisms are complicated and research is ongoing but in general subcutaneous fat is more stable and produces more beneficial molecules than visceral fat. Subcutaneous fat for example produces the hormone leptin, which acts on the brain to suppress appetite and burn stored fat and larger volumes of adiponectin, which is thought to protect against diabetes by regulating the processing of fats and sugars. Visceral fat on the other hand is unstable, constantly being broken down and rebuilt. It also produces a precursor to angiotensin, a protein that causes blood vessels to constrict and blood pressure to rise and secretes more of retinol-binding protein 4 (RBP4), a molecule that increases insulin resistance. Visceral fat also produces inflammatory cytokines increasing inflammation and its proximity to the liver boosts the production of LDL (bad) cholesterol (9,10).
As with BMI measurement in children is more complicated as sizes differ hugely between girls and boys and due to different rates of growth at different times. A waist circumference dataset is available as part of the British 1990 Growth Reference (UK90) and although this can be used to grade individual children on a centile scale, there are currently no recommended centile thresholds to show increased risk (11). A 2006 study of British children aged 5-16 suggested that a waist to height ratio of 0.5 or greater might prove a useful threshold but further research is needed (12). What is known is that like in adults, children with high waist measurements for their age have poor health outcomes, being 5-6x more likely to develop metabolic syndrome by the time they are in their mid-twenties than their peers.
To measure your waist you first need to find the bottom of your ribs and the top of your hips – your waist is midway between these points. Wrap the tape measure around this point and breathe out naturally (13).
Learn more about the use of waist measurement in our Nutrition & Weight Management course
REFERENCES:
(1) Vague J. La differentiation sexuelle. Facteur determinant des formes de l’obesit. Press Med. 1947;30:339-40.
(2) Ohlson et al (1985). The influence of body fat distribution on the incidence of diabetes mellitus. 13.5 years of follow-up of the participants in the study of men born in 1913. Diabetes. 1985;34:1055-8.
(3). Larsson et al (1984) Abdominal adipose tissue distribution, obesity, and risk of cardiovascular disease and death: 13 year follow up of participants in the study of men born in 1913. Br Med J (Clin Res Ed). 1984;288:1401-4.
(4) Cerhan et al (2014) A pooled Analysis of Waist Circumference and Mortality in 650,000 Adults. Mayo Clin Proc 89(3). 335-345.
(5) Grundy et al (2005). Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Circulation. 2005;112:2735-52.
(6). International Diabetes Federation (2006). The IDF consensus worldwide definition of metabolic syndrome. Brussels. 2006.
(7) World Health Organization (2011). Definition, Diagnosis, and Classification of Diabetes Mellitus and its Complications: Report of a WHO Consultation. Part I: Diagnosis and Classification of Diabetes Mellitus. Geneva: World Health Organization. 1999. Assessed on January 26, 2011.
(8) NHS Choices (Sept 2016) http://www.nhs.uk/chq/Pages/849.aspx?CategoryID=51
(9) Despres JP. Health consequences of visceral obesity. Ann Med. 2001;33:534-41.
(10) Guifen Qiang et al (2016) The obesity-induced transcriptional regulator TRIP-Br2 mediates visceral fat endoplasmic reticulum stress-induced inflammation. Nature Communications, 2016; 7: 11378 DOI: 10.1038/ncomms11378
(11) McCarthy HD, Jarrett KV, Crawley HF. The development of waist circumference percentiles in British children aged 5.0-16.9 y. European Journal of Clinical Nutrition 2001; 55: 902-7.
(12) McCarthy HD, Ashwell M. A study of central fatness using waist-to-height ratios in UK children and adolescents over two decades supports the simple message – ‘keep your waist circumference to less than half your height’. International Journal of Obesity 2006; 30: 988-92.
(13) NHS Choices guidance for waist measurement http://www.nhs.uk/chq/Pages/849.aspx?CategoryID=51