There may be health risks in progressively reducing our energy (kilojoule) intake to match our
ever-falling energy (kilojoule) expenditure. For one thing, there have been at least three studies
which show that people who have a higher energy intake live longer. One of these studies, from
the Dutch town of Zutphen, indicated that the increased longevity was associated either with
more physical activity or with a less efficient metabolism (i.e. burning up a lot of energy without
doing extra exercise).
At the very least, there are difficulties in achieving an adequate intake of all essential nutrients
from food alone when the amount of food eaten only containing 4200 kilojoules (1000
kilocalories) or less per day.