Long term (3-6 months) community studies which require visits to the Human Nutrition Unit research clinic for blood tests and other measurements – study participants continue their usual home life attending clinical visits to collect dietary test components and for study measurements. Long term studies allow the testing of products such as putative weight loss agents to be trialed.

Many of these studies are of a 'parallel' design, where participants are randomised into either the treatment or the control arm of the trial.