Beer : Health and Nutrition

4 The Basics of Human Nutrition
If we are to make reasoned judgements on the interrelationship of beer and human health,
then it is important that we rst consider the key elements of nutrition.
Essentially our bodies require, in the correct balance, the key nutrients for healthy
functioning and development. Additionally the diet should be devoid of materials that
are damaging. In this context there may be components of our daily intake that, while
not of themselves essential nutrients, may serve to counter negative impacts of adverse
food constituents or materials present in the environment. For more detailed considerations
of human nutrition the reader is referred to Boyle and Zyla (1996).
Our bodies need food to provide energy (calories) and the building blocks of our tissues
(notably amino acids), for the most part taken into the body in the form of protein,
carbohydrates, lipids, vitamins, minerals and water. Our wellbeing is therefore incontrovertibly
related to what we eat and drink, in terms of the content of the essentials,
the form in which they are present in the food (e.g. carbohydrate in the form of bre
acts bene cially in a way quite distinct from that carbohydrate that will overtly provide
energy through digestion) and the presence or absence of molecules in the food that
may be bene cial or damaging to the body.
If any individual component of the diet is present in excess or is insuf cient in
quantity, then the diet is out of balance.
Energy
The main sources of energy for the human body are carbohydrates, fats and proteins.
However, especially in the context of this book, we must stress that alcohol is a source
of energy.
Energy in food is quanti ed on the basis of calories, one calorie being de ned as the
amount of heat required to raise the temperature of one gram of water by one degree
Celsius. It is customary to talk in terms of kilocalories (or Calories with a capital C)
which equate to 1000 calories. These days it is more scienti cally correct to talk in terms
of kilojoules, for the joule has replaced the calorie as the primary unit of energy under
the international system of units (SI). (Incidentally, James Prescott Joule, 1818–89, after
whom the unit of energy was named, was a member of a famous Staffordshire brew-