Study investigator retired and study not funded

The purpose of this study is to find out if drinking extra water helps people prevent or relieve headaches and hunger and, if so, what volume of water is most effective and when is it best to drink it?

If participants decide to participate in this trial, they will be asked to drink a specific amount of water at particular times of the day for 14 days. A computer will decide by chance the amount of water they will be asked to drink each day of the trial and the times at which to drink this.

There are different amounts and different times that people will be asked to drink water, this is so that the investigators can find out if there is an optimal volume of water to drink, and a best time to drink water to reduce headaches or hunger. The least amount of water the computer could ask participants to drink is half a glass (that is 4oz or 120ml). The largest volume of water the computer could ask participants to drink would be eight glasses of water a day (a total of 64oz or 2L) spread across the day (that is not all at once). Once the computer has assigned participants to a particular volume and times to drink water, these will remain the same for every day throughout the study.

Participants will be asked to provide some brief information about themselves at the beginning of the study (for example, age, sex, height and whether you exercise, smoke or not). During the study they will be asked to weigh themselves and record this, Their dietary habits and the amount they drink will be kept on a private and confidential page on the study website. They will be asked to fill in [2] confidential short surveys about how they feel and their views, one at the start and one at the end of the study.

Inclusion Criteria

• Any adult (defined as someone aged 18 or above) for whom advice to drink extra water is not contraindicated.

Exclusion Criteria

General exclusions

• < 18 years of age
• No personal email address
• Pregnancy
• Ecstasy recreational drug use

Exclusions Health Conditions

• Impaired renal function
• Chronic bowel problems
• Low sodium levels
• Diabetes insipidus
• Schizophrenia or history of psychosis
• Anorexia or bulimia
• Congestive heart failure
• Current chemotherapy treatment

Exclusions Concurrent Medications

• Taking regular non-steroidal anti-inflammatory drugs
• Diuretics (e.g. thiazides, indapamide, loop diuretics), also called "water tablets"
• Anti-depressants: Selective serotonin re-uptake inhibitors (SSRIs), Tricyclic and tetracyclic antidepressants (TCAs),monoamine oxidase inhibitor (MAOIs)
• Anti-psychotics (e.g. haloperidol)
• Anti-convulsants (e.g. sodium valproate, carbamazepine)
• Cancer drugs (anti-neoplastic agents)

Implicit exclusions

• People without internet access
• People who cannot read
• People without the ability to understand the website and informed consent documents