Effects of a 6-week hypocaloric diet on changes in body composition, hunger, and subsequent weight regain in healthy young and older adults

Recent studies have suggested a short-term impairment in the regulation of food intake in older adults, but further studies are needed to determine if a Longer-term impairment exists and to identify underlying causes. Changes in body weight and composition were measured over a 6-week underfeeding st udy and a G-month follow-up period in healthy young (n = 23) and older (OLD , n = 18) men and women. The young adults were either normal weight (YNW, n = 12) or overweight (YOW, n = 11). Energy intakes during underfeeding were 896 +/- 18 (SEM) keal less than weight-maintenance energy requirements det ermined prior to underfeeding. In addition, changes in perceived hunger dur ing underfeeding were monitored in a subgroup (n = 19). OLD and YOW subject s lust significantly more weight during underfeeding than did YNW subjects (p =.025 and .000, respectively), and they did not gain back significant we ight in the 6-month follow-up. In addition, OLD subjects reported a signifi cantly lower frequency of hunger during underfeeding (p, =.05). There was n o significant difference among groups in the relationship between rr-eight lost and fat-free mass test. Wealthy OLD adults have an impaired ability to regulate food intake over at least 6 months following underfeeding compare d with YNW adults, and a reduction in their perceived frequency of hunger m ay be a contributing factor.