Your brain is strongly influenced by your hydration status.
Studies show that even mild dehydration, such as the loss of 1–3% of body weight, can impair many aspects of brain function.
In a study in young women, researchers found that fluid loss of 1.4% after exercise impaired both mood and concentration. It also increased the frequency of headaches (6Trusted Source).
Many members of this same research team conducted a similar study in young men. They found that fluid loss of 1.6% was detrimental to working memory and increased feelings of anxiety and fatigue (7).
A fluid loss of 1–3% equals about 1.5–4.5 pounds (0.5–2 kg) of body weight loss for a person weighing 150 pounds (68 kg). This can easily occur through normal daily activities, let alone during exercise or high heat.
Drinking plenty of water can help you lose weight. So get an office water cooler!
This is because water can increase satiety and boost your metabolic rate.
Some evidence suggests that increasing water intake can promote weight loss by slightly increasing your metabolism, which can increase the number of calories you burn on a daily basis.
A 2013 study in 50 young women with overweight demonstrated that drinking an additional 16.9 ounces (500 mL) of water 3 times per day before meals for 8 weeks led to significant reductions in body weight and body fat compared with their pre-study measurements (27Trusted Source).
The timing is important too. Drinking water half an hour before meals is the most effective. It can make you feel more full so that you eat fewer calories