When we contact the unsuspecting person, thereafter known as a mere
‘subject’, who has offered, or in most cases is randomly selected, to take
part in a nutritional study, the task of keeping a food diary can seem all
too easy. But keeping a written record of everything you eat and drink is
not that simple.

More often than not, we ask the person not only to write down everything
consumed, but to weigh it, preferably as individual ingredients. And if
that sounds a challenging task, think of the individual who, at a later
date, will have to translate the quantitative descriptions into numerical
data and finally into nutritional information.

Whenever I am training people in the art of keeping a food diary, I
usually say that I do not care what they eat (of course, being a concerned
nutritionist, I do). The main point is that they write down everything actually
consumed for, say, a week and not what they think they ought to be eating.

The knowledge that their every mouthful will be nutritionally scrutinised
can in itself be daunting. While subjects do not usually go to the extent
of having their jaws wired, they may change their eating habits. For example,
there is a strong tendency to cheat – perhaps by resisting those titbits
that stave off the hunger pangs between meals. But temptation may be too
strong, or the willpower too weak. The alternative is to forget, accidentally
on purpose, to record snacks and ‘naughty-but-nice’ delights in the diary.
It is all very well, but these foods count towards the overall nutritional
composition of the diet. And this is what the nutritionist is striving to
look at.

Some people are reluctant to reveal their eating patterns and require
subtle prompting. Some are often apologetic, writing footnotes, sometimes
tongue-in-cheek, justifying why they pigged out on bombay mix, chicken madras
and the works the previous night. The honest food-diarists will confess
all, admitting to the amount of alcohol drunk at that party, and the contents
of the midnight feast they ate when they got home. One subject even kept
a written tally on his arm of the number of pints he had at the pub, to
make sure he would not forget before he reached home.

Eating out while keeping a food diary can be an embarrassing exercise.
Producing your diary at the dinner table provokes strange looks from your
fellow diners, and even more so from the restaurateur. Then comes the ultimate
embarrassment of asking the chef or waiter for the ingredients of the meal
you have just eaten, so you can write it in the diary. You may be treated
with suspicion, mistaken as an environmental health inspector, or even removed
from the establishment, but at least you are helping the cause of nutritional
research.

Nutritional surveys are usually targeted at defined age ranges or groups
of the population. It’s said, never work with children or animals. I find,
however, that most children are surprisingly cooperative subjects. The only
problem is interpreting the bizarre names of some of the new confectionary.
What on earth is a Raspberry Wobbler? The food diary is not the only method
we use to assess eating patterns. Because it intrudes on people’s normal
eating habits, it may not always give an accurate reflection of the diet.
Nevertheless, it is an important tool in nutritional studies, as are the
subjects taking part. Without them we would not be able to obtain the data
required to assess dietary habits and to look at the relationship between
diet, health and wellbeing.

If you are ever lucky enough to be selected for a dietary study which
involves keeping a food diary, you may see your diet in a completely new
light, for better or worse, fatter or thinner.

Julie Loughridge is a nutritionist who works at the AFRC Institute of
Food Research in Norwich. She recently worked at New ÐÓ°ÉÔ­´´ magazine
as a British Association Media Fellow.

Delegates at a symposium held earlier this month at Farnborough by the
Royal Aeronautical Society, discussed how technologies currently under development
could lead to windowless cockpits. Such a cockpit in, for example, a fighter
plane, could be in the centre of the aircraft, where there is more space.
It could also be a self-contained unit that would then be ejected as a whole
in an emergency.

Structurally, an aircraft without windows would be stronger. Don Jarrett,
from the Royal Aerospace Establishment, says that the enclosed cockpit could
be advantageous in high-performance aircraft, where aerodynamics could be
optimised by removing the unnecessary windows.

Helmet-mounted displays are a development of two technologies already
in use in some military aircraft. One is night vision goggles, which are
mounted on the pilot’s helmet. These are sensitive to very low light levels
and infrared light just outside the visible spectrum which is given out
by the terrain making it visible at night.

The other technology, known as head-up displays, projects information
onto the inside of the cockpit’s windscreen so that the pilot can read it
without taking his eyes off the terrain outside. The pilot does not then
lose the possibly vital seconds it takes to refocus the eyes downwards onto
the aircraft’s control panels.

These technologies could be combined into future helmet-mounted displays.
Pictures from the exterior camera would appear instantaneously in the display.
Sensors on the helmet would detect movements of the pilot’s head which in
turn would control the direction of the camera so the pilot could get an
all around view, including directly downwards.

The pilot would have a better field of view than from a normal cockpit,
where the canopy obscures vision to right and left. Information about the
aircraft’s systems and status would be projected directly onto the helmet’s
screens.

Having two screens in the helmet would give each eye a slightly different
view of an image, producing a strong 3D picture. Stereoscopic vision could
be useful for separating distant scenic information from close-up instruments.