Show Summary Details
Page of



Philip James

Page of

PRINTED FROM OXFORD MEDICINE ONLINE ( © Oxford University Press, 2022. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy and Legal Notice).

date: 16 May 2022

Obesity is of increasing public health importance. Recent increases in life expectancy in high-income countries may be threatened by the rapid rise in the prevalence of obesity and associated health problems, including diabetes mellitus. Obesity has also emerged as an increasing concern in many middle-income countries. This chapter begins by analysing definitions of obesity, including older standard values of weight-for-height, more recent classifications based on body mass index (BMI) for adults and children, as well as classifications of abdominal obesity based on waist circumference. The association of anthropometric indices with ethnic origins is discussed and the rationale for population-specific criteria for abdominal obesity is outlined. Application of these criteria in population surveys from 191 countries around the year 2000 suggest that there were about 1.1 billion overweight and obese adults in the world of whom 320 million were obese with BMI of 30 kg/m2 or more. More than half of overweight people are in middle- or low-income countries. About 10 per cent of boys and 9 per cent of girls aged 5–17 years are overweight, based on recently developed international standard criteria. Obesity is associated with a range of morbidity including well-known associations with diabetes and coronary heart disease and less appreciated impacts on respiratory function, sleep, and back and joint pains that contribute to diminished physical activity. Obesity is estimated to be one of the three risk factors that contribute most to the global burden of disability-adjusted life years lost (DALYs). Preventive interventions must target adults as well as children because it is in adult life that the greatest increases in obesity and its complications occur. Overweight and obesity result from small errors in energy balance, which lead to weight increments and the persistence of weight gain. In high-income countries, physical activity and energy expenditure have declined due to decrease in physical activity in work, commuting, and domestic activities while leisure-time physical activities have remained stable. Overall energy intakes have been declining. Interventions to reduce overweight and obesity must be made at individual, community, and societal levels. These may include changes in the physical environment that promote safe physical activity; economic measures using incentives or taxes to promote change; policy interventions to encourage, for example, breast feeding within healthcare settings; and sociocultural interventions including strategies for health promotion.

Access to the complete content on Oxford Medicine Online requires a subscription or purchase. Public users are able to search the site and view the abstracts for each book and chapter without a subscription.

Please subscribe or login to access full text content.

If you have purchased a print title that contains an access token, please see the token for information about how to register your code.

For questions on access or troubleshooting, please check our FAQs, and if you can't find the answer there, please contact us.