The effect of hydration status on appetite and energy intake

Abstract

This study investigated the effects of hydration status and fluid availability on appetite and energy intake. Sixteen males completed four 24 h trials, visiting the laboratory overnight fasted on two consecutive days. Standardised foods were provided during the 24 h and on day two an ad-libitum semi-solid porridge breakfast was provided. Water intake during the 24 h (0 or 40 mL•kg -1 ) and fluid provision during the ad-libitum breakfast were manipulated so subjects were euhydrated with (EU-F) and without fluid (EU-NF) available at breakfast; and hypohydrated with (HYPO-F) and without fluid (HYPO-NF) available at breakfast. Blood samples (0 and 24 h), urine samples (0-24 h) and subjective responses (0, 24 and 24.5 h) were collected. HYPO trials decreased body mass by ~1.8%. Serum and urine osmolality increased and plasma volume decreased during HYPO trials (P<0.001). Total urine output was greater during EU than HYPO trials (P<0.001). Ad-libitum energy intake was not different between trials: 2658 (938) kJ (EU-F), 2353 (643) kJ (EU-NF),2295 (529) kJ (HYPO-F), 2414 (954) kJ (HYPO-NF), (P=0.131). Fluid intake was ~200 mL greater during HYPO-F than EU-F (P<0.01). There was an interaction effect for thirst (P<0.001), but not hunger or fullness. These results demonstrate that mild hypohydration produced by inadequate fluid intake and fluid availability during eating does not influence ad-libitum energy intake of a semi-solid breakfast, at least in healthy young males.3

Effect of hydration status and fluid availability on ad-libitum energy intake of a semi-solid breakfast

“…Alterations in hydration status might also influence appetite regulation and a previous study reported that acylated ghrelin was reduced after exerciseinduced dehydration compared to when euhydration was maintained (Kelly et al, 2012), but that there was no change in peptide YY or pancreatic polypeptide. Neither the present study nor that of Corney et al (2015) observed any differences in acylated ghrelin between hypohydration and euhydration. The divergent findings between studies might be accounted for by the different protocols used to induce hypohydration.…”

“…Similarly, Engell (1988) reported a reduction in energy intake during 6 meals over 48 h when fluid was restricted at meal times. In contrast, two recent studies (Corney et al, 2015;Kelly, Guelfi, Wallman, & Fairchild, 2012) observed no difference in ad-libitum energy intake between euhydrated and hypohydrated (2-3% body mass loss) conditions, with hypohydration induced using a combination of exercise and fluid restriction. In contrast to the studies of Shirreffs et al (2004) and Engell (1988), Kelly et al (2012) and Corney et al (2015) provided fluid during feeding.…”

“…In contrast, two recent studies (Corney et al, 2015;Kelly, Guelfi, Wallman, & Fairchild, 2012) observed no difference in ad-libitum energy intake between euhydrated and hypohydrated (2-3% body mass loss) conditions, with hypohydration induced using a combination of exercise and fluid restriction. In contrast to the studies of Shirreffs et al (2004) and Engell (1988), Kelly et al (2012) and Corney et al (2015) provided fluid during feeding. Taken together with the animal literature, these studies suggest that whilst fluid restriction might result in hypohydration, it might be the fluid restriction during eating rather than the presence of hypohydration at the start of the meal that reduces energy intake in humans.…”

“…Hypohydration might develop rapidly due to an acute loss of body water due to either exercise or heat exposure (Corney, Sunderland, & James, 2015) or more slowly due to a chronic inadequate fluid intake (James & Shirreffs, 2013). Whilst hypohydration appears to be more prevalent among athletes competing in certain sports, it is also common in children (Stookey, Brass, Holliday, & Arieff, 2012), the elderly (Lavizzo-Mourey, 1987), as well as the general adult population (Mears & Shirreffs, 2014).…”

Habits of fluid and electrolytes intake in elite athletes

“…If an athlete is undergoing high-intensity or prolonged duration training without ingesting enough fluid, a risk of dehydration occurs because fluid loss through sweating can exceed the athlete's ability to ingest and absorb the fluid. Changes in the hydration status can, after the training, affect the ingestion of food, as well as some other aspects of recovery (4). To minimize the negative effects of dehydration, voluntary drinking to ensure a hydrated state prior to and during exercise is recommended (5).…”