Hydration status affects thirst and salt preference but not energy intake or postprandial ghrelin in healthy adults: A randomised crossover trial

What Was Tested

This randomized controlled trial paper looks at Ghrelin.

To investigate the effect of hydration status on multiple facets of appetite.

Why It Was Studied

Few studies have investigated the effect of hydration status on appetite for food in healthy adults.

However, an extensive investigation into both the psychological and physiological appetitive responses to hydration status has never been conducted.

Who Took Part

The study group was 16 participants.

PubMed indexes the participants as young adults and adults, both men and women.

After 3 days pre-trial standardization, a range of appetite tasks were conducted when hypohydrated (HYPO) and euhydrated (EUHY) in 16 healthy participants (8 men).

Hydration status was manipulated via dehydration in a heat tent for 60 min and subsequent fluid restriction (HYPO) or replacement (EUHY).

How the Study Was Run

The design is described as randomized and crossover.

Random assignment meant chance, not the researchers, decided who got Ghrelin and who got the comparison, which limits bias.

In the crossover set-up each of the participants took both Ghrelin and the comparison in turn, acting as their own control.

A time span of 3 days appears in the methods.

The next day, a food reward computer task was completed followed by an ad libitum pasta meal.

Pre- and post-prandial visual analogue scales assessing hunger, fullness, and flavour desires (sweet, salty, savoury and fatty) were additionally completed.

Blood samples were taken the previous day before the hydration interventions in a euhydrated state, and in the fasted and post-prandial state during HYPO and EUHY.

What Was Measured

PubMed files the paper under topics including Dehydration, Energy Intake, Food Preferences, Ghrelin, Hunger, Organism Hydration Status and Postprandial Period.

Author keywords: Appetite, Copeptin, Desire and Water intake.

What This Means in Plain Language

The paper is a randomized and crossover study of Ghrelin in 16 participants over 3 days.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

Results are reported in around 6 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 2019 (Physiology & behavior), a journal based in United States.

More context: the Ghrelin compound page, all human trials.