The effects of different temperatures of post-exercise protein-containing drink on gastric motility and energy intake in healthy young men

Consumption of hot protein-containing drink accelerates gastric emptying rate and is associated with higher hunger levels in older adults

Meal temperature is known to affect gastric emptying and appetite. While protein intake is recommended for older age, gastric emptying is delayed with age, resulting in loss of appetite. This study aimed to investigate whether adjusting the temperature of protein-containing drinks could improve gastric emptying and appetite in older individuals. Twenty male and female participants aged 65 years and older underwent three one-day trials in random order. Participants visited the laboratory after a 10-hour fast and consumed 200 mL of protein-containing drink dissolved in 13C-sodium acetate at 4°C, 37°C, or 60°C in a 3-minute period. Then, participants sat in a chair for 90 minutes to measure gastric emptying rate by the 13C-sodium acetate breath test and subjective appetite by a visual analog scale. The results showed that 37°C and 60°C drinks had faster gastric emptying at 5 and 10 min after ingestion than did the 4°C drink (trial-time interaction, p = 0.014). Tmax-calc, an indicator of gastric emptying rate, tended to be faster for the 37°C and 60°C drinks than for the 4°C drink (49.7 ± 17.5 min vs. 44.1 ± 18.5 min vs. 45.3 ± 25.8 min for the 4°C, 37°C, and 60°C, respectively; p = 0.085). There were no significant differences in the change in hunger from baseline among the three different temperature drinks (p > 0.05). Only in the 60°C trial, a shorter gastric emptying time was associated with greater hunger (r=-0.554, p = 0.021). These findings suggest that hot protein-containing drinks may accelerate gastric emptying and contribute to rapid nutrient intake and increased appetite in older adults.

EFFECTS OF EXERCISE ON HUMAN ENERGY METABOLISM IN HIGH TEMPERATURE AND HIGH HUMIDITY ENVIRONMENT

ABSTRACT Introduction Many exercise enthusiasts have started participating in sports in the high-temperature environment in recent years due to the increasing popularity of these sports habits. However, their scientific studies still have a gap in their safety and effectiveness. Objective Measure the energy supply characteristics of fat and sugar oxidation during exercise in different high-temperature and humidity environments. Methods 20 healthy adult subjects were exposed to fixed-intensity exercise for 20 minutes at 30-33 oC, 20% relative humidity (RH), and 50% RH, respectively. Results Under the silent exposure condition, compared with RH 20% and RH 50% under high temperature, sugar oxidation was significantly increased (P<0.01), while fat oxidation was significantly reduced (P<0.01), and total energy consumption was significantly increased (P<0.01). Under the condition of 65% VO2 max exercise, compared with RH 20% and RH 50% at high temperatures, the amount of sugar oxidation was significantly reduced (P<0.05), and the total energy consumption was significantly reduced (P<0.05). Conclusion Under 65% exercise under VO2 max in the high temperature and humidity-controlled environment, the high temperature and medium humidity (RH 50%) environment consumes more energy, and there is a greater amount of sugar oxidation. Level of evidence II; Therapeutic studies - investigating treatment outcomes.

Effects of different temperatures of carbohydrate-protein-containing drinks on gastric emptying rate after exercise in healthy young men: randomized crossover trial

Background

The present study examined the effects of different temperatures of carbohydrate-protein-containing drinks after exercise on the subsequent gastric emptying rate in healthy young men.

Methods

Twelve healthy young men completed two, 1-day trials in random order. In both trials, the participants completed intermittent cycling exercise for 20 min, consisting of a 120% heart rate peak for 20 s, followed by 25 W for 40 s. Participants consumed 400 mL of carbohydrate-protein-containing drink (0.85 MJ) at 4 °C (EX + 4 °C) or 60 °C (EX + 60 °C) over a 5-min period after exercise. The participants sat on a chair for 2.5 h to measure their gastric emptying rate using the ¹³C-sodium acetate breath test. Subjective feelings of gastrointestinal discomfort and appetite were measured using a visual analog scale. Interstitial fluid glucose levels after drinking were measured using a continuous glucose-monitoring device.

Results

The percentage excretion of ¹³CO₂ tended to be higher at EX + 60 °C than at EX + 4 °C from the start of the test until 30 min after drink ingestion (5.7 ± 0.5 vs. 6.5 ± 0.4%dose/h for the EX + 4 °C and EX + 60 °C trials, respectively; effect sizes [ES] = 0.277, p = 0.065). The time of maximum ¹³CO₂ emissions per hour (Tmax-calc) and the time of half ¹³CO₂ emissions per hour (T_1/2) did not differ between trials. Subjective gastrointestinal discomfort was lower at EX + 60 °C compared to EX + 4 °C (ES = 0.328, p = 0.041). There were no significant differences in interstitial fluid glucose levels between the different temperatures of carbohydrate-protein-containing drinks after exercise (p = 0.698).

Conclusions

Consumption of warm carbohydrate-protein-containing drinks after exercise may accelerate gastric emptying in the very early phase and may reduce gastric discomfort.

Trial registration

University Hospital Medical Information Network, UMIN000045626. Registered on June 10, 2021.