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Salt Intake, Hydration Status and Gastrointestinal Discomfort During Fasting

The Effect of Low and High Salt Intake on Hydration Status and Gastrointestinal Discomfort During Seven Hours of Dry Fasting

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05839860
Enrollment
23
Registered
2023-05-03
Start date
2023-02-14
Completion date
2023-07-31
Last updated
2023-09-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

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.

Interventions

OTHERSalt 3 g

Placebo group taking a breakfast meal and 3g salt on tomatoes before fasting for 7 hours

OTHERSalt 6 g

Intervention group taking a breakfast meal and 6g salt on tomatoes plus 1 L water before fasting for 7 hours

OTHERSalt 9 g

Intervention group taking a breakfast meal and 9g salt on tomatoes plus 1 L water before fasting for 7 hours

Sponsors

Oxford Brookes University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)

Eligibility

Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
Urine specific gravity 7 hours7 hoursUrine specific gravity at 7 hours after starting fasting
Urinary sodium 7 hours7 hoursUrinary sodium at 7 hours after starting fasting
Urinary potassium baseline0 hoursUrinary potassium at baseline before starting fasting
Urinary potassium 1 hour1 hourUrinary potassium at 1 hour after starting fasting
Urinary potassium 2 hours2 hoursUrinary potassium at 2 hours after starting fasting
Urinary potassium 3 hours3 hoursUrinary potassium at 3 hours after starting fasting
Urinary potassium 4 hours4 hoursUrinary potassium at 4 hours after starting fasting
Urinary potassium 5 hours5 hoursUrinary potassium at 5 hours after starting fasting
Urinary potassium 6 hours6 hoursUrinary potassium at 6 hours after starting fasting
Urinary potassium 7 hours7 hoursUrinary potassium at 7 hours after starting fasting
Urine colour baseline0 hoursUrine colour at baseline before starting fasting
Urine colour 1 hour1 hourUrine colour at 1 hour after starting fasting
Urine colour 2 hours2 hoursUrine colour at 2 hours after starting fasting
Urine colour 3 hours3 hoursUrine colour at 3 hours after starting fasting
Urine colour 4 hours4 hoursUrine colour at 4 hours after starting fasting
Urine colour 5 hours5 hoursUrine colour at 5 hours after starting fasting
Urine colour 6 hours6 hoursUrine colour at 6 hours after starting fasting
Urine colour 7 hours7 hoursUrine colour at 7 hours after starting fasting
Urine specific gravity baseline0 hoursUrine specific gravity at baseline before starting fasting
Urine specific gravity 1 hour1 hourUrine specific gravity at 1 hour after starting fasting
Urine specific gravity 2 hours2 hoursUrine specific gravity at 2 hours after starting fasting
Urine specific gravity 3 hours3 hoursUrine specific gravity at 3 hours after starting fasting
Urine specific gravity 4 hours4 hoursUrine specific gravity at 4 hours after starting fasting
Urine specific gravity 5 hours5 hoursUrine specific gravity at 5 hours after starting fasting
Urine specific gravity 6 hours6 hoursUrine specific gravity at 6 hours after starting fasting
Total urine production 6 hours6 hoursVolume of urine produced at at 6 hours after starting fasting
Total urine production 7 hours7 hoursVolume of urine produced at at 7 hours after starting fasting
Total urine production 4 hours4 hoursVolume of urine produced at at 4 hours after starting fasting
Total urine production 5 hours5 hoursVolume of urine produced at at 5 hours after starting fasting
Total urine production baseline0 hourVolume of urine produced at baseline
Total urine production 1 hour1 hourVolume of urine produced at 1 hour after starting fasting
Total urine production 2 hours2 hoursVolume of urine produced at at 2 hours after starting fasting
Total urine production 3 hours3 hoursVolume of urine produced at at 3 hours after starting fasting
Body weight baseline0 hoursBody weight at baseline before fasting
Body weight 1 hour1 hourBody weight at 1 hour after starting fasting
Body weight 2 hours2 hoursBody weight at 2 hours after starting fasting
Body weight 3 hours3 hoursBody weight at 3 hours after starting fasting
Body weight 4 hours4 hoursBody weight at 4 hours after starting fasting
Body weight 5 hours5 hoursBody weight at 5 hours after starting fasting
Body weight 6 hours6 hoursBody weight at 6 hours after starting fasting
Body weight 7 hours7 hoursBody weight at 7 hours after starting fasting
Urinary sodium baseline0 hoursUrinary sodium at baseline before starting fasting
Urinary sodium 1 hour1 hourUrinary sodium at 1 hour after starting fasting
Urinary sodium 2 hours2 hoursUrinary sodium at 2 hours after starting fasting
Urinary sodium 3 hours3 hoursUrinary sodium at 3 hours after starting fasting
Urinary sodium 4 hours4 hoursUrinary sodium at 4 hours after starting fasting
Urinary sodium 5 hours5 hoursUrinary sodium at 5 hours after starting fasting
Urinary sodium 6 hours6 hoursUrinary sodium at 6 hours after starting fasting

Secondary

MeasureTime frameDescription
Gastrointestinal discomfort 1 hour1 hourGastrointestinal 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 2 hours2 hoursGastrointestinal 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 hoursGastrointestinal 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 4 hours4 hoursGastrointestinal 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 5 hours5 hoursGastrointestinal 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.
Gastrointestinal discomfort 6 hours6 hoursGastrointestinal 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.
Gastrointestinal discomfort 7 hours7 hoursGastrointestinal 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 hoursSystolic and Diastolic Blood Pressure at baseline before starting fasting
Blood Pressure 1 hour1 hourSystolic and Diastolic Blood Pressure at 1 hour after starting fasting
Blood Pressure 2 hours2 hoursSystolic and Diastolic Blood Pressure at 2 hours after starting fasting
Blood Pressure 3 hours3 hoursSystolic and Diastolic Blood Pressure at 3 hours after starting fasting
Blood Pressure 4 hours4 hoursSystolic and Diastolic Blood Pressure at 4 hours after starting fasting
Blood Pressure 5 hours5 hoursSystolic and Diastolic Blood Pressure at 5 hours after starting fasting
Blood Pressure 6 hours6 hoursSystolic and Diastolic Blood Pressure at 6 hours after starting fasting
Blood Pressure 7 hours7 hoursSystolic and Diastolic Blood Pressure at 7 hours after starting fasting
Perception of thirst at baseline0 hoursPerception 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 1 hour1 hourPerception 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 hoursPerception 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 hoursPerception 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.
Perception of thirst at 4 hours4 hoursPerception 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 hoursPerception 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 6 hours6 hoursPerception 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.
Perception of thirst at 7 hours7 hoursPerception 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.
Gastrointestinal discomfort baseline0 hoursGastrointestinal 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.

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026