Middle-aged women who motivate themselves to eat healthily
have a lower body mass index than those who do so in order to
keep others happy, new University of Otago research suggests.
The Department of Human Nutrition study of 1600 women aged
between 40 and 50 is the first nationwide research of its
The participants were asked to rate the degree to which
different motivations for eating healthily applied to them.
They were also surveyed on their specific food and eating
Study co-author Dr Caroline Horwath said that more
self-determined and autonomous reasons for eating healthily
included enjoying creating healthy meals or viewing eating
healthily as integral to one's lifestyle or values.
More "controlled" motivation, on the other hand, involved
reasons such as being nagged to eat healthily or feeling
expected to do so.
Dr Horwath said the results clearly showed that the more
self-determined or autonomous a woman's style of motivation
for eating healthily, the lower her body mass index (BMI).
"We found that every 10-unit increase in women's scores for
autonomous motivation to eat healthily was associated with a
1.4kg lower body weight, which was equivalent to a 2 per cent
lower BMI in a woman of average BMI in this sample."
The results suggest that even a modest decrease in controlled
motivation could equate to nearly 1kg lower weight, she says.
"As women in this age bracket are known to be at high risk of
weight gain, this amount of weight loss could be important in
reducing their risk of diabetes and cardiovascular disease,"
The research appears in the September issue of the Journal
of the Academy of Nutrition and Dietetics.