Caroline G. MacIntosh

Relation between food intake and visual analogue scale ratings of appetite and other sensations in healthy older and young subjects

Objective: Visual analogue scales are widely used in appetite research, yet the validity of these scales to evaluate appetite and mood has not been assessed in older subjects. The aim of this study was to determine the relations between food intake and visual analogue scale (VAS) ratings of appetite and nonappetite sensations in healthy older and young subjects.Design: Retrospective combined analysis of four single-blind, randomised, controlled appetite studies.Setting: All studies were conducted in the University of Adelaide, Department of Medicine, Adelaide, Australia.Subjects: A total of 45 healthy young men (n=24) and women (n=21) aged 18–35 y and 45 healthy older men (n=24) and women (n=21) aged 65–85 y were recruited by advertisement.Interventions: Oral, intraduodenal or intravenous administration of treatments which suppressed food intake were compared to control. Up to 90 min after treatment, a test meal was offered and subjects ate freely for between 30 and 60 min. Perceptions were assessed by 100-mm visual analogue scales administered at regular intervals.Results: Food intake at the test meal was positively related to perceptions of hunger, drowsiness, and calmness at both baseline and premeal (r>0.16, P<0.05), and inversely related to premeal ratings of fullness (r> 0.2, P<0.05) in both older and young subjects. Food intake was related to VAS ratings at least as strongly, if not more so, in older as in young subjects.Conclusions: These observations (i) confirm that food intake is related to perceptions of hunger and fullness as assessed by VAS in healthy older and young subjects, and (ii) suggest that sensations, not obviously associated with appetite, including ‘drowsiness’ and ‘calmness’, are also associated with food intake.

The nutritional status of 250 older Australian recipients of domiciliary care services and its association with outcomes at 12 months.

OBJECTIVES: To identify predictors and consequences of nutritional risk, as determined by the Mini Nutritional Assessment (MNA), in older recipients of domiciliary care services living at home.

Effect of small intestinal nutrient infusion on appetite, gastrointestinal hormone release, and gastric myoelectrical activity in young and older men

OBJECTIVE:The mechanisms responsible for the reduction in appetite and slowing of gastric emptying in older persons are poorly understood. The aim of this study was to evaluate the effects of aging on small intestinal regulation of appetite, GI hormone release, and gastric myoelectrical activity.METHODS:Thirteen older (65–84 yr) and 13 young (18–32 yr) healthy men received isovolumetric, intraduodenal (ID) infusions of saline (control), lipid, and glucose for 120 min, on separate days. The energy content of the lipid and glucose infusions was identical at 2.86 kcal/min. Immediately after the ID infusions, each subject was offered a buffet meal, and ad libitum food intake was quantified. Blood glucose and plasma insulin, glucagon-like peptide 1, and glucose-dependent insulinotropic peptide were measured. Gastric myoelectrical activity was measured by surface electrogastrography (EGG).RESULTS:ID lipid suppressed food intake in both the young and older men (p < 0.05), whereas ID glucose suppressed food intake only in the older men (p < 0.05). The blood glucose (p < 0.01) and insulin (p < 0.05) responses to ID glucose were greater in older than young men. However, there were no differences in glucagon-like peptide 1 or glucose-dependent insulinotropic peptide responses to any of the infusions. There was a greater increase in the EGG power ratio both during and after ID glucose infusion in the young (p < 0.05) than the older men, and an attenuation of EGG frequency by nutrient infusions in older, but not young, men.CONCLUSIONS:Our findings indicate that aging is associated with nutrient-specific changes in appetite, hormonal, and gastric myoelectrical (EGG) responses to ID nutrients. An enhanced satiating effect of small intestinal carbohydrates may potentially contribute to the anorexia of aging.

Guar gum reduces postprandial hypotension in older people.

OBJECTIVE: To determine whether slowing of gastric emptying and glucose absorption with guar gum would reduce the fall in blood pressure after an oral glucose load in older subjects.

Effects of aging on the opioid modulation of feeding in humans.

OBJECTIVES: To determine whether aging is associated with a reduction in the opioid modulation of feeding, which may be important in the pathogenesis of the “anorexia of aging.”

The effect of acute hyperglycaemia on appetite and food intake in Type 1 diabetes mellitus

Aims  To determine the effects of acute hyperglycaemia on appetite and food intake in Type 1 diabetes mellitus.

Effect of a lacto-ovo vegetarian diet on fasting small intestinal motility

Background: Changes in diet can alter gastric and small intestinal (SI) motility. The effects of a vegetarian diet on fasting SI motility are unknown. Methods: Manometric studies were performed in 9 lacto-ovo vegetarians (7 women) and 9 omnivores (7 women) of similar age and body mass index. On each study day, manometry was used to assess SI motility for 5 h, or 3 complete cycles of the interdigestive motor complex (IDMC). Lacto-ovo vegetarians were studied once; omnivores were studied twice, on their usual diet, and after consuming a 14-day lacto-ovo vegetarian diet. Diet diaries were kept for 5 days prior to each manometric study. Data were analysed for dietary composition and for cycle length and duration of each phase (I, II and III) of the IDMC. Results:BACKGROUND Changes in diet can alter gastric and small intestinal (SI) motility. The effects of a vegetarian diet on fasting SI motility are unknown. METHODS Manometric studies were performed in 9 lacto-ovo vegetarians (7 women) and 9 omnivores (7 women) of similar age and body mass index. On each study day, manometry was used to assess SI motility for 5 h, or 3 complete cycles of the interdigestive motor complex (IDMC). Lacto-ovo vegetarians were studied once: omnivores were studied twice, on their usual diet, and after consuming a 14-day lacto-ovo vegetarian diet. Diet diaries were kept for 5 days prior to each manometric study. Data were analysed for dietary composition and for cycle length and duration of each phase (I, II and III) of the IDMC. RESULTS Dietary intake did not differ between chronic vegetarians and chronic omnivores apart from a trend to higher fibre intake (29 +/- 3 versus 20 +/- 3 g/day; P = 0.058). Omnivores eating a vegetarian diet showed a trend to decreased alcohol consumption (P = 0.068), but did not increase their fibre intake (20 +/- 3 versus 21 +/- 3 g/day). Neither cycle length nor duration of each IDMC phase differed between chronic vegetarians and chronic omnivores. After 14 days of a vegetarian diet, omnivores had a reduction in cycle length (128 +/- 19 versus 86 +/- 12 min; P = 0.02), with a non-significant reduction of Phase II (99 +/- 20 versus 50 +/- 8 min: P = 0.066). CONCLUSIONS A chronic vegetarian diet has no major effect on fasting SI motility; but acute dietary change may alter the cycle length and component phases of the IDMC.