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Salt Intake, Hydration Status and Gastrointestinal Discomfort During Fasting

Not Applicable
Completed
Conditions
Healthy
Interventions
Other: Salt 3 g
Other: Salt 6 g
Other: Salt 9 g
Registration Number
NCT05839860
Lead Sponsor
Oxford Brookes University
Brief Summary

This study is part of a hyperhydration project and it has been designed based on a scoping review (Hyperhydration in healthy adults: a scoping review on different methodologies and vehicles utilized) and a previous study (Dietary patterns and gastrointestinal discomfort during Ramadan in a UK Muslim population). The current study aims to examine the impact of different levels of salt intake (6 \& 9 grams) with \[15 milliliters per kilogram of bodyweight (ml/ kg/ bw)\] of water intake during 7 hours of dry fasting compared to a control group (3g salt) under the state of water balance (euhydrated). A previous study and a review by the authors highlighted the potential negative impact of salt and fasting on gastrointestinal (GI) discomfort; hence, the potential negative side effects on gastrointestinal (GI) discomfort during the intervention period will be investigated. By studying a hyperhydration protocol, this research will help the population to reduce dehydration during dry fasting. By doing so, it may improve the quality of life during Ramadan fasting.

Detailed Description

Dry fasting has been reported to cause changes in body weight, lipid profile, blood pressure, glucose level, metabolism, hormones homeostasis, and hydration status. A scoping review by the investigators highlighted that dehydration had been linked to changes in plasma volume and osmolality (concentration of all chemical particles), urine volume and osmolality, blood pressure, glucocorticoid hormones, body weight loss, negative impact on mood, irritability, short-term memory, and work productivity. It has been reported that prolonged dry fasting can contribute to a loss of up to 1.5 kg in body weight on the day after fasting. This weight loss is associated with loss of body water.

Hyperhydration (overhydration) has not yet been defined. However, any improvement in the fluid matrix in the plasma volume is considered hyperhydration. Simulating hyperhydration strategies, such as those used by athletes competing in long-distance events and in hot environments, has the potential to reduce the level of dehydration during dry fasting.

Sodium and water intake have essential roles in maintaining and improving the fluid matrix in plasma. By investigating the relationship between sodium and water intake on biomarkers such as urine sodium concentration, blood pressure, speed of urine production, urine colour, urine specific gravity, and net body fluid balance, it is possible to distinguish the impact of hyperhydration protocols on hydration levels.

The primary aim of this study is to examine the impact of salt intake (6 \& 9 g/l) on the level of hydration by measuring urine sodium, urine potassium, urine production, and changes in body weight compared to the control group during 8 hours of dry fasting. The secondary outcome of this study will be the impact of the hyperhydration protocol on GI discomfort.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
23
Inclusion Criteria
  • Aged 18 to 45
  • BMI between 18.5 and 29.9
  • No higher (140/90mmHg) or lower (80/60mmHg) blood pressure
  • Non-pregnant or lactating
  • No diabetes (type 1 & 2)
  • No gastrointestinal disease such as inflammatory bowel disease (IBD) or Irritable bowel syndrome (IBS)
  • No disease including the common cold and high cholesterol (total cholesterol above 5 mmol/l)
  • No covid symptoms
  • No allergy to the food in the meal list and tomatoes
Exclusion Criteria
  • Aged <18 or >45 years
  • BMI between <18.5 or > 29.9
  • Higher (>140/90mmHg) or lower (<80/60mmHg) blood pressure
  • Pregnant or lactating
  • Having diabetes (type 1 & 2)
  • Having gastrointestinal disease such as inflammatory bowel disease (IBD) or Irritable bowel syndrome (IBS)
  • Having disease including the common cold and high cholesterol (total cholesterol above 5 mmol/l)
  • Having covid symptoms
  • Having allergy to the food in the meal list and tomatoes

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
3 g saltSalt 3 gTomatoes with 3 g salt
6 g saltSalt 6 gTomatoes with 6 g salt and 1 L of water
9 g saltSalt 9 gTomatoes with 9 g salt and 1 L of water
Primary Outcome Measures
NameTimeMethod
Urine colour 5 hours5 hours

Urine colour at 5 hours after starting fasting

Urine colour 6 hours6 hours

Urine colour at 6 hours after starting fasting

Urine colour 7 hours7 hours

Urine colour at 7 hours after starting fasting

Body weight 2 hours2 hours

Body weight at 2 hours after starting fasting

Urinary potassium 2 hours2 hours

Urinary potassium at 2 hours after starting fasting

Urine colour 1 hour1 hour

Urine colour at 1 hour after starting fasting

Total urine production 1 hour1 hour

Volume of urine produced at 1 hour after starting fasting

Body weight 7 hours7 hours

Body weight at 7 hours after starting fasting

Urinary sodium 3 hours3 hours

Urinary sodium at 3 hours after starting fasting

Urinary sodium 4 hours4 hours

Urinary sodium at 4 hours after starting fasting

Urinary sodium 6 hours6 hours

Urinary sodium at 6 hours after starting fasting

Urinary potassium 1 hour1 hour

Urinary potassium at 1 hour after starting fasting

Total urine production 4 hours4 hours

Volume of urine produced at at 4 hours after starting fasting

Total urine production baseline0 hour

Volume of urine produced at baseline

Total urine production 3 hours3 hours

Volume of urine produced at at 3 hours after starting fasting

Body weight 3 hours3 hours

Body weight at 3 hours after starting fasting

Body weight 4 hours4 hours

Body weight at 4 hours after starting fasting

Urinary sodium 2 hours2 hours

Urinary sodium at 2 hours after starting fasting

Total urine production 2 hours2 hours

Volume of urine produced at at 2 hours after starting fasting

Total urine production 6 hours6 hours

Volume of urine produced at at 6 hours after starting fasting

Total urine production 7 hours7 hours

Volume of urine produced at at 7 hours after starting fasting

Body weight baseline0 hours

Body weight at baseline before fasting

Body weight 1 hour1 hour

Body weight at 1 hour after starting fasting

Body weight 5 hours5 hours

Body weight at 5 hours after starting fasting

Body weight 6 hours6 hours

Body weight at 6 hours after starting fasting

Urinary potassium 3 hours3 hours

Urinary potassium at 3 hours after starting fasting

Total urine production 5 hours5 hours

Volume of urine produced at at 5 hours after starting fasting

Urinary sodium 7 hours7 hours

Urinary sodium at 7 hours after starting fasting

Urinary potassium 7 hours7 hours

Urinary potassium at 7 hours after starting fasting

Urine specific gravity baseline0 hours

Urine specific gravity at baseline before starting fasting

Urine specific gravity 1 hour1 hour

Urine specific gravity at 1 hour after starting fasting

Urine specific gravity 3 hours3 hours

Urine specific gravity at 3 hours after starting fasting

Urinary sodium baseline0 hours

Urinary sodium at baseline before starting fasting

Urinary sodium 1 hour1 hour

Urinary sodium at 1 hour after starting fasting

Urinary sodium 5 hours5 hours

Urinary sodium at 5 hours after starting fasting

Urinary potassium 4 hours4 hours

Urinary potassium at 4 hours after starting fasting

Urinary potassium 5 hours5 hours

Urinary potassium at 5 hours after starting fasting

Urine specific gravity 4 hours4 hours

Urine specific gravity at 4 hours after starting fasting

Urine specific gravity 5 hours5 hours

Urine specific gravity at 5 hours after starting fasting

Urinary potassium baseline0 hours

Urinary potassium at baseline before starting fasting

Urine colour 2 hours2 hours

Urine colour at 2 hours after starting fasting

Urine colour 3 hours3 hours

Urine colour at 3 hours after starting fasting

Urine colour 4 hours4 hours

Urine colour at 4 hours after starting fasting

Urine specific gravity 2 hours2 hours

Urine specific gravity at 2 hours after starting fasting

Urine specific gravity 7 hours7 hours

Urine specific gravity at 7 hours after starting fasting

Urinary potassium 6 hours6 hours

Urinary potassium at 6 hours after starting fasting

Urine colour baseline0 hours

Urine colour at baseline before starting fasting

Urine specific gravity 6 hours6 hours

Urine specific gravity at 6 hours after starting fasting

Secondary Outcome Measures
NameTimeMethod
Gastrointestinal discomfort baseline0 hours

Gastrointestinal discomfort at baseline before starting fasting using a Gastrointestinal Symptoms Questionnaire to measure 1.Abdominal pain 2.Epigastric pain (pain or discomfort right below your ribs in the area of your upper abdomen) 3. Heartburn 4. Regurgitation 5. Abdominal rumbling 6. Bloating 7. Empty feeling 8. Nausea 9. Vomiting 10. Loss of appetite 11. Postprandial fullness (an unpleasant sensation like prolonged persistence of food in the stomach) 12. belching (otherwise known as burping or eructation) 13. Flatulence (buildup of gas in the digestive system that can lead to abdominal discomfort) on a 7 point scale labelled 0 for none, 1 for mild, 2 for moderate, 3 for quite a lot, 4 for severe, 5 for very severe, 6 for unbearable. Higher scores mean worst outcome.

Gastrointestinal discomfort 4 hours4 hours

Gastrointestinal discomfort at 4 hours after starting fasting using a Gastrointestinal Symptoms Questionnaire to measure 1.Abdominal pain 2.Epigastric pain (pain or discomfort right below your ribs in the area of your upper abdomen) 3. Heartburn 4. Regurgitation 5. Abdominal rumbling 6. Bloating 7. Empty feeling 8. Nausea 9. Vomiting 10. Loss of appetite 11. Postprandial fullness (an unpleasant sensation like prolonged persistence of food in the stomach) 12. belching (otherwise known as burping or eructation) 13. Flatulence (buildup of gas in the digestive system that can lead to abdominal discomfort) on a 7 point scale labelled 0 for none, 1 for mild, 2 for moderate, 3 for quite a lot, 4 for severe, 5 for very severe, 6 for unbearable. Higher scores mean worst outcome.

Gastrointestinal discomfort 1 hour1 hour

Gastrointestinal discomfort at 1 hour after starting fasting using a Gastrointestinal Symptoms Questionnaire to measure 1.Abdominal pain 2.Epigastric pain (pain or discomfort right below your ribs in the area of your upper abdomen) 3. Heartburn 4. Regurgitation 5. Abdominal rumbling 6. Bloating 7. Empty feeling 8. Nausea 9. Vomiting 10. Loss of appetite 11. Postprandial fullness (an unpleasant sensation like prolonged persistence of food in the stomach) 12. belching (otherwise known as burping or eructation) 13. Flatulence (buildup of gas in the digestive system that can lead to abdominal discomfort) on a 7 point scale labelled 0 for none, 1 for mild, 2 for moderate, 3 for quite a lot, 4 for severe, 5 for very severe, 6 for unbearable. Higher scores mean worst outcome.

Gastrointestinal discomfort 7 hours7 hours

Gastrointestinal discomfort at 7 hours after starting fasting using a Gastrointestinal Symptoms Questionnaire to measure 1.Abdominal pain 2.Epigastric pain (pain or discomfort right below your ribs in the area of your upper abdomen) 3. Heartburn 4. Regurgitation 5. Abdominal rumbling 6. Bloating 7. Empty feeling 8. Nausea 9. Vomiting 10. Loss of appetite 11. Postprandial fullness (an unpleasant sensation like prolonged persistence of food in the stomach) 12. belching (otherwise known as burping or eructation) 13. Flatulence (buildup of gas in the digestive system that can lead to abdominal discomfort) on a 7 point scale labelled 0 for none, 1 for mild, 2 for moderate, 3 for quite a lot, 4 for severe, 5 for very severe, 6 for unbearable. Higher scores mean worst outcome.

Blood Pressure baseline0 hours

Systolic and Diastolic Blood Pressure at baseline before starting fasting

Blood Pressure 2 hours2 hours

Systolic and Diastolic Blood Pressure at 2 hours after starting fasting

Blood Pressure 4 hours4 hours

Systolic and Diastolic Blood Pressure at 4 hours after starting fasting

Perception of thirst at 1 hour1 hour

Perception of thirst at 1 hour after starting fasting using a 7 point scale labelled as 1=not thirsty at all, 2=not thirsty, 3=not very thirsty, 4=neutral, 5=thirsty, 6=very thirsty and 7=very, very thirsty.

Perception of thirst at 2 hours2 hours

Perception of thirst at 2 hours after starting fasting using a 7 point scale labelled as 1=not thirsty at all, 2=not thirsty, 3=not very thirsty, 4=neutral, 5=thirsty, 6=very thirsty and 7=very, very thirsty.

Perception of thirst at 3 hours3 hours

Perception of thirst at 3 hours after starting fasting using a 7 point scale labelled as 1=not thirsty at all, 2=not thirsty, 3=not very thirsty, 4=neutral, 5=thirsty, 6=very thirsty and 7=very, very thirsty.

Blood Pressure 6 hours6 hours

Systolic and Diastolic Blood Pressure at 6 hours after starting fasting

Gastrointestinal discomfort 2 hours2 hours

Gastrointestinal discomfort at 2 hours after starting fasting using a Gastrointestinal Symptoms Questionnaire to measure 1.Abdominal pain 2.Epigastric pain (pain or discomfort right below your ribs in the area of your upper abdomen) 3. Heartburn 4. Regurgitation 5. Abdominal rumbling 6. Bloating 7. Empty feeling 8. Nausea 9. Vomiting 10. Loss of appetite 11. Postprandial fullness (an unpleasant sensation like prolonged persistence of food in the stomach) 12. belching (otherwise known as burping or eructation) 13. Flatulence (buildup of gas in the digestive system that can lead to abdominal discomfort) on a 7 point scale labelled 0 for none, 1 for mild, 2 for moderate, 3 for quite a lot, 4 for severe, 5 for very severe, 6 for unbearable. Higher scores mean worst outcome.

Gastrointestinal discomfort 3 hours3 hours

Gastrointestinal discomfort at 3 hours after starting fasting using a Gastrointestinal Symptoms Questionnaire to measure 1.Abdominal pain 2.Epigastric pain (pain or discomfort right below your ribs in the area of your upper abdomen) 3. Heartburn 4. Regurgitation 5. Abdominal rumbling 6. Bloating 7. Empty feeling 8. Nausea 9. Vomiting 10. Loss of appetite 11. Postprandial fullness (an unpleasant sensation like prolonged persistence of food in the stomach) 12. belching (otherwise known as burping or eructation) 13. Flatulence (buildup of gas in the digestive system that can lead to abdominal discomfort) on a 7 point scale labelled 0 for none, 1 for mild, 2 for moderate, 3 for quite a lot, 4 for severe, 5 for very severe, 6 for unbearable. Higher scores mean worst outcome.

Gastrointestinal discomfort 5 hours5 hours

Gastrointestinal discomfort at 5 hours after starting fasting using a Gastrointestinal Symptoms Questionnaire to measure 1.Abdominal pain 2.Epigastric pain (pain or discomfort right below your ribs in the area of your upper abdomen) 3. Heartburn 4. Regurgitation 5. Abdominal rumbling 6. Bloating 7. Empty feeling 8. Nausea 9. Vomiting 10. Loss of appetite 11. Postprandial fullness (an unpleasant sensation like prolonged persistence of food in the stomach) 12. belching (otherwise known as burping or eructation) 13. Flatulence (buildup of gas in the digestive system that can lead to abdominal discomfort) on a 7 point scale labelled 0 for none, 1 for mild, 2 for moderate, 3 for quite a lot, 4 for severe, 5 for very severe, 6 for unbearable. Higher scores mean worst outcome.

Blood Pressure 3 hours3 hours

Systolic and Diastolic Blood Pressure at 3 hours after starting fasting

Blood Pressure 5 hours5 hours

Systolic and Diastolic Blood Pressure at 5 hours after starting fasting

Blood Pressure 7 hours7 hours

Systolic and Diastolic Blood Pressure at 7 hours after starting fasting

Perception of thirst at 6 hours6 hours

Perception of thirst at 6 hours after starting fasting using a 7 point scale labelled as 1=not thirsty at all, 2=not thirsty, 3=not very thirsty, 4=neutral, 5=thirsty, 6=very thirsty and 7=very, very thirsty.

Gastrointestinal discomfort 6 hours6 hours

Gastrointestinal discomfort at 6 hours after starting fasting using a Gastrointestinal Symptoms Questionnaire to measure 1.Abdominal pain 2.Epigastric pain (pain or discomfort right below your ribs in the area of your upper abdomen) 3. Heartburn 4. Regurgitation 5. Abdominal rumbling 6. Bloating 7. Empty feeling 8. Nausea 9. Vomiting 10. Loss of appetite 11. Postprandial fullness (an unpleasant sensation like prolonged persistence of food in the stomach) 12. belching (otherwise known as burping or eructation) 13. Flatulence (buildup of gas in the digestive system that can lead to abdominal discomfort) on a 7 point scale labelled 0 for none, 1 for mild, 2 for moderate, 3 for quite a lot, 4 for severe, 5 for very severe, 6 for unbearable. Higher scores mean worst outcome.

Blood Pressure 1 hour1 hour

Systolic and Diastolic Blood Pressure at 1 hour after starting fasting

Perception of thirst at baseline0 hours

Perception of thirst at baseline before starting fasting using a 7 point scale labelled as 1=not thirsty at all, 2=not thirsty, 3=not very thirsty, 4=neutral, 5=thirsty, 6=very thirsty and 7=very, very thirsty.

Perception of thirst at 4 hours4 hours

Perception of thirst at 4 hours after starting fasting using a 7 point scale labelled as 1=not thirsty at all, 2=not thirsty, 3=not very thirsty, 4=neutral, 5=thirsty, 6=very thirsty and 7=very, very thirsty.

Perception of thirst at 5 hours5 hours

Perception of thirst at 5 hours after starting fasting using a 7 point scale labelled as 1=not thirsty at all, 2=not thirsty, 3=not very thirsty, 4=neutral, 5=thirsty, 6=very thirsty and 7=very, very thirsty.

Perception of thirst at 7 hours7 hours

Perception of thirst at 7 hours after starting fasting using a 7 point scale labelled as 1=not thirsty at all, 2=not thirsty, 3=not very thirsty, 4=neutral, 5=thirsty, 6=very thirsty and 7=very, very thirsty.

Trial Locations

Locations (1)

Oxford Brookes Centre for Nutrition and Health

🇬🇧

Oxford, United Kingdom

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