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Horm Metab Res 2014; 46(05): 365-369
DOI: 10.1055/s-0033-1357205
Endocrine Care
© Georg Thieme Verlag KG Stuttgart · New York

The Thermic Effect of Food is Reduced in Older Adults

S. Du   *
1   Shanghai Jiao Tong University School of Medicine, Shanghai, China
2   Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA
,
T. Rajjo   *
2   Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA
,
S. Santosa
3   Department of Exercise Science, Concordia University, Montreal, QC, Canada
,
M. D. Jensen
2   Endocrine Research Unit, Mayo Clinic, Rochester, MN, USA
› Author Affiliations
Further Information

Publication History

received 02 August 2013

accepted 24 September 2013

Publication Date:
23 October 2013 (online)

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Abstract

The thermic effect of food accounts for ̴ 10% of daily energy expenditure. A reduction in the thermic effect of food, which has been variably observed in the older adults, could predispose to fat gain. We tested whether the thermic effect of food is reduced in older adults compared with young adults by analyzing our database of standardized studies conducted at the Mayo Clinic between 1999 and 2009. Data were available from 136 older adult volunteers aged 60–88 (56 females) and 141 young adults aged 18–35 years (67 females). Basal energy expenditure was measured by indirect calorimetry to assess basal metabolic rate. Body fat, fat free mass, and visceral fat were measured using a combination of dual energy X-ray absorptiometry and an abdominal CT scan. The thermic effect of food and postprandial insulinemia were measured in 123 older adults (52 females) and 86 young adults (38 females) of these volunteers. Basal metabolic rate adjusted for fat-free mass was less in older adults (p=0.01) and the thermic effect of food was ̴ 1% (p=0.02) less in the older adults. After controlling for meal size and fat-free mass, body fat and fat distribution did not predict the thermic effect of food. Both basal metabolic rate and the thermic effect of food are less in older adults than young adults, even when they have similar amounts of lean tissue and consume a similar size meal. These factors contribute to lower daily energy expenditure in the older adults.

Key words

indirect calorimetry - resting metabolic rate - body composition - body fat - insulin

* Denotes equal contribution to this work.