From February 2017, information about the work of the MRC/CSO Social and Public Health Sciences Unit, University of Glasgow is available and updated on the University of Glasgow website.

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Researchers have discovered that middle age spread seems to have an effect on waistlines but not weight as people get older.

Age, Weight and Waistlines

posted on: Aug 17, 2007


Researchers, funded by the Medical Research Council, have found that people in early middle age seem to put on more weight more quickly than people slightly older. But the waistlines of the older group seem to grow more quickly.


One of the researchers Geoff Der, from the MRC's Social and Public Health Sciences Unit in Glasgow explained:


"As people get older it seems that their bodies change... they lose muscle and get fatter - this explains why middle-age spread might not be reflected on the bathroom scales."

He goes on: "This challenges the traditional method of measuring how fat a person is: the body mass index. The BMI is a good measure of lean body tissue, but an expanding waistline may be a more reliable measure of the amount of fatty tissue a person has gained. Although the people in the older middle age group in this study appeared to put on less weight than the younger people, their waist circumferences continued to grow over time. What appears to have been happening is that the increase in fat was being obscured by a loss of muscle mass.''


The researchers carried out a nine-year study of 1044 people aged either 39 or 59 in 1991. The height, waist circumference and weight of each participant was measured in 1991, 1995 and 2000, and used to measure changes in body mass index over time.


Only one in five (20%) of the people maintained a stable weight as the study progressed. Steady weight gain was measured in the younger group, more than 42% of study participants put on 10kg, 17% gained 5kg.


On average, both men and women in the younger group gained between 0.5kg and 1kg a year. This weight gain was fastest in their younger years. Those in the older age group gained least weight in the second half of the study, however, although their overall weight may not have changed their waist circumference did.


No difference in weight gain was found between men and women and it was the same no matter what career the person followed.


The research forms part of the Medical Research Council funded Twenty-07 study.


Original research paper:

Changes in weight and waist circumference over 9 years in a Scottish population.

European Journal of Clinical Nutrition, July 2007.


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