A new method to assess daily energy intake using a seven day diary and camera-phone.

Over the past decades, the prevalence of obesity has increased dramatically
{Flegal, 2002; Visscher, 2002}. Overweight or obesity is caused by an imbalance
between energy intake and energy expenditure where even the smallest imbalance
can lead to large changes in body weight over time. To study causes and
consequences of obesity and other diseases related to energy imbalance,
accurate and precise techniques are needed to assess both food intake and
physical activity, the latter being the most variable component of energy
expenditure. Whereas these parameters can be accurately assessed under
laboratory conditions, assessing food intake and physical activity in daily
life is still a methodological challenge.
By comparing reported energy intake with measured total energy expenditure
(TEE), misreporting becomes visible. The golden standard for the assessment of
TEE under daily life conditions is doubly labeled water (DLW). Validation
studies with DLW show that misreporting is mainly a matter of underreporting.
On the other hand, overreporting can also occur in some populations, e.g.
depleted patients, and might overestimate the health situation of these
patients.

The aim of this project is to improve dietary intake assessment using a novel
technique, compare it with the existing methodology and validate it against
total energy expenditure.
a. Improve dietary intake assessment using a 7-day food record in combination
with a camera-phone and compare it with the traditional weighed record.
b. Validate this new technique against total energy expenditure as assessed
with a tri-axial accelerometer.

Subjects fill out a 7-day food record twice, once by means of a weighed food
record and once a record without weighing in combination with a camera-phone.
Hence, all measurements will be performed twice. The design will be a
randomized crossover design with 1 week between the two trials.
Underreporting will be assessed by comparing energy intake with total energy
expenditure (TEE) calculated from 7 days physical activity assessment with an
accelerometer.
Underrecording and undereating, the two components of underreporting will be
assessed by measuring water loss and body mass change respectively, a technique
also previously developed at our laboratory {Goris, 2000}.
In summary, all measurements that will be performed are:
- the assessment of body weight and height
- the assessment of physical activity
- the assessment of water loss over a week interval
- the assessment of energy intake with a 7-day food diary (1 week a weighed
food record, 1 week a food record in combination with a camera-phone)

The burden associated with participation is low. No risks are to be expected.