How to Become Smarter - Spender, Charles (mobi)

This text describes techniques for improving mental abilities. Some of the things
it can help you to achieve include the following:

Depending on circumstances, use different lifestyles that improve one or
another mental function.
Experience euphoria without drugs and come up with new ideas, when
needed.
Slow down and prevent yourself from making rash, impulsive decisions,
when necessary.
Sharpen your wit, become more talkative, and entertain people.
When necessary, lower your mood and increase emotional tension, which
can reduce procrastination.
Increase your score on intelligence or general aptitude tests.
Concentrate on reading and writing for many hours daily.
Increase your grade point average if you are a student or improve your job
productivity if you are a knowledge worker.

The proposed methods are brief cooling or heating of the body (water therapy)
and three different "smart diets," each suitable for a different type of task.
Despite its technical content, the book is written in an accessible language and
has an informative summary for each chapter and a list of key points at the end
of each section. The book supports most of the claims in the bulleted list above
with a theory and the author's personal experience (a healthy subject). Previously
published scientific studies directly support about a half of these claims, including
the claim about intelligence tests.