2.3. Needs for research

1. The data from existing studies should be examined to identify, if possible, factors that determine the extremes of individual variations and their associations.

2. More longitudinal information is needed about BMR and fat mass in the prepregnant state and in the first trimester.

3. The preliminary evidence obtained so far on a decrease in physical activity in pregnancy needs to be strengthened by measurements of total energy expenditure with doubly-labelled water. Studies of this kind are already under way in Thailand and in the Philippines.

4. If a decrease in total energy expenditure is found, it is necessary to examine whether this response has any drawbacks for the individual, family or community.

5. Studies should be undertaken in clearly undernourished populations.