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Completed

NCT Number: NCT05839860

Salt Intake, Hydration Status and Gastrointestinal Discomfort During Fasting

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.

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Key information

Conditions

Healthy

Age range

18 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Oxford Brookes Centre for Nutrition and Health

Oxford, OX3 0BP, United Kingdom

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Salt 3 g

Other

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

Salt 6 g

Other

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

Salt 9 g

Other

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

Primary outcomes

  1. Total urine production baseline

    Time frame: 0 hour

    Volume of urine produced at baseline

  2. Total urine production 1 hour

    Time frame: 1 hour

    Volume of urine produced at 1 hour after starting fasting

  3. Total urine production 2 hours

    Time frame: 2 hours

    Volume of urine produced at at 2 hours after starting fasting

  4. Total urine production 3 hours

    Time frame: 3 hours

    Volume of urine produced at at 3 hours after starting fasting

  5. Total urine production 4 hours

    Time frame: 4 hours

    Volume of urine produced at at 4 hours after starting fasting

  6. Total urine production 5 hours

    Time frame: 5 hours

    Volume of urine produced at at 5 hours after starting fasting

  7. Total urine production 6 hours

    Time frame: 6 hours

    Volume of urine produced at at 6 hours after starting fasting

  8. Total urine production 7 hours

    Time frame: 7 hours

    Volume of urine produced at at 7 hours after starting fasting

  9. Body weight baseline

    Time frame: 0 hours

    Body weight at baseline before fasting

  10. Body weight 1 hour

    Time frame: 1 hour

    Body weight at 1 hour after starting fasting

  11. Body weight 2 hours

    Time frame: 2 hours

    Body weight at 2 hours after starting fasting

  12. Body weight 3 hours

    Time frame: 3 hours

    Body weight at 3 hours after starting fasting

  13. Body weight 4 hours

    Time frame: 4 hours

    Body weight at 4 hours after starting fasting

  14. Body weight 5 hours

    Time frame: 5 hours

    Body weight at 5 hours after starting fasting

  15. Body weight 6 hours

    Time frame: 6 hours

    Body weight at 6 hours after starting fasting

  16. Body weight 7 hours

    Time frame: 7 hours

    Body weight at 7 hours after starting fasting

  17. Urinary sodium baseline

    Time frame: 0 hours

    Urinary sodium at baseline before starting fasting

  18. Urinary sodium 1 hour

    Time frame: 1 hour

    Urinary sodium at 1 hour after starting fasting

  19. Urinary sodium 2 hours

    Time frame: 2 hours

    Urinary sodium at 2 hours after starting fasting

  20. Urinary sodium 3 hours

    Time frame: 3 hours

    Urinary sodium at 3 hours after starting fasting

  21. Urinary sodium 4 hours

    Time frame: 4 hours

    Urinary sodium at 4 hours after starting fasting

  22. Urinary sodium 5 hours

    Time frame: 5 hours

    Urinary sodium at 5 hours after starting fasting

  23. Urinary sodium 6 hours

    Time frame: 6 hours

    Urinary sodium at 6 hours after starting fasting

  24. Urinary sodium 7 hours

    Time frame: 7 hours

    Urinary sodium at 7 hours after starting fasting

  25. Urinary potassium baseline

    Time frame: 0 hours

    Urinary potassium at baseline before starting fasting

  26. Urinary potassium 1 hour

    Time frame: 1 hour

    Urinary potassium at 1 hour after starting fasting

  27. Urinary potassium 2 hours

    Time frame: 2 hours

    Urinary potassium at 2 hours after starting fasting

  28. Urinary potassium 3 hours

    Time frame: 3 hours

    Urinary potassium at 3 hours after starting fasting

  29. Urinary potassium 4 hours

    Time frame: 4 hours

    Urinary potassium at 4 hours after starting fasting

  30. Urinary potassium 5 hours

    Time frame: 5 hours

    Urinary potassium at 5 hours after starting fasting

  31. Urinary potassium 6 hours

    Time frame: 6 hours

    Urinary potassium at 6 hours after starting fasting

  32. Urinary potassium 7 hours

    Time frame: 7 hours

    Urinary potassium at 7 hours after starting fasting

  33. Urine colour baseline

    Time frame: 0 hours

    Urine colour at baseline before starting fasting

  34. Urine colour 1 hour

    Time frame: 1 hour

    Urine colour at 1 hour after starting fasting

  35. Urine colour 2 hours

    Time frame: 2 hours

    Urine colour at 2 hours after starting fasting

  36. Urine colour 3 hours

    Time frame: 3 hours

    Urine colour at 3 hours after starting fasting

  37. Urine colour 4 hours

    Time frame: 4 hours

    Urine colour at 4 hours after starting fasting

  38. Urine colour 5 hours

    Time frame: 5 hours

    Urine colour at 5 hours after starting fasting

  39. Urine colour 6 hours

    Time frame: 6 hours

    Urine colour at 6 hours after starting fasting

  40. Urine colour 7 hours

    Time frame: 7 hours

    Urine colour at 7 hours after starting fasting

  41. Urine specific gravity baseline

    Time frame: 0 hours

    Urine specific gravity at baseline before starting fasting

  42. Urine specific gravity 1 hour

    Time frame: 1 hour

    Urine specific gravity at 1 hour after starting fasting

  43. Urine specific gravity 2 hours

    Time frame: 2 hours

    Urine specific gravity at 2 hours after starting fasting

  44. Urine specific gravity 3 hours

    Time frame: 3 hours

    Urine specific gravity at 3 hours after starting fasting

  45. Urine specific gravity 4 hours

    Time frame: 4 hours

    Urine specific gravity at 4 hours after starting fasting

  46. Urine specific gravity 5 hours

    Time frame: 5 hours

    Urine specific gravity at 5 hours after starting fasting

  47. Urine specific gravity 6 hours

    Time frame: 6 hours

    Urine specific gravity at 6 hours after starting fasting

  48. Urine specific gravity 7 hours

    Time frame: 7 hours

    Urine specific gravity at 7 hours after starting fasting

Secondary outcomes

  1. Gastrointestinal discomfort baseline

    Time frame: 0 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.

  2. Gastrointestinal discomfort 1 hour

    Time frame: 1 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.

  3. Gastrointestinal discomfort 2 hours

    Time frame: 2 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.

  4. Gastrointestinal discomfort 3 hours

    Time frame: 3 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.

  5. Gastrointestinal discomfort 4 hours

    Time frame: 4 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.

  6. Gastrointestinal discomfort 5 hours

    Time frame: 5 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.

  7. Gastrointestinal discomfort 6 hours

    Time frame: 6 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.

  8. Gastrointestinal discomfort 7 hours

    Time frame: 7 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.

  9. Blood Pressure baseline

    Time frame: 0 hours

    Systolic and Diastolic Blood Pressure at baseline before starting fasting

  10. Blood Pressure 1 hour

    Time frame: 1 hour

    Systolic and Diastolic Blood Pressure at 1 hour after starting fasting

  11. Blood Pressure 2 hours

    Time frame: 2 hours

    Systolic and Diastolic Blood Pressure at 2 hours after starting fasting

  12. Blood Pressure 3 hours

    Time frame: 3 hours

    Systolic and Diastolic Blood Pressure at 3 hours after starting fasting

  13. Blood Pressure 4 hours

    Time frame: 4 hours

    Systolic and Diastolic Blood Pressure at 4 hours after starting fasting

  14. Blood Pressure 5 hours

    Time frame: 5 hours

    Systolic and Diastolic Blood Pressure at 5 hours after starting fasting

  15. Blood Pressure 6 hours

    Time frame: 6 hours

    Systolic and Diastolic Blood Pressure at 6 hours after starting fasting

  16. Blood Pressure 7 hours

    Time frame: 7 hours

    Systolic and Diastolic Blood Pressure at 7 hours after starting fasting

  17. Perception of thirst at baseline

    Time frame: 0 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.

  18. Perception of thirst at 1 hour

    Time frame: 1 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.

  19. Perception of thirst at 2 hours

    Time frame: 2 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.

  20. Perception of thirst at 3 hours

    Time frame: 3 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.

  21. Perception of thirst at 4 hours

    Time frame: 4 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.

  22. Perception of thirst at 5 hours

    Time frame: 5 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.

  23. Perception of thirst at 6 hours

    Time frame: 6 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.

  24. Perception of thirst at 7 hours

    Time frame: 7 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.

Sponsors and collaborators

Lead sponsor

Oxford Brookes University

Other

Registry information

Official study title

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

Important dates

Study start
2023
Primary completion
2023
Study completion
2023
First posted
May 3, 2023
Registry last updated
Sep 6, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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