Skip to main content
UKCRC Health Research Classification System

Diet, obesity and nutrition

Advice on health categories

The coding for studies on obesity, diet and nutrition will depend on the nature of the research.

Use Metabolic and Endocrine for investigation of metabolic disorders or dietary metabolism. Mental Health is appropriate for studies of eating disorders and Oral and Gastrointestinal should be used to code for studies of absorption from the gut.

Only use the following standardised breakdown of health categories and percentages for general studies on nutrition, obesity or poor diet where there is no other indication of disease area:

Health Category Percentage
Cancer and neoplasms 20
Cardiovascular 20
Metabolic and Endocrine 20
Oral and Gastrointestinal 20
Stroke 20

Note that this standardised breakdown is shared with research on physical activity and exercise.

Advice on research activities

Obesity is considered a risk factor for other diseases. Therefore, interventions to reduce obesity should be coded as 3 Prevention, even if the person is already obese. Use 5 Treatment Development or 6 Treatment Evaluation for studies focussed on treatment of an existing obesity-related disease and in cases of secondary prevention (additional guidance on differentiating secondary and primary prevention is also available).

There are three main research activity code groups typically associated with diet and nutrition research:

  • 3 Prevention for studies focussed on preventing ill health or promoting well being.
    • Use 3.1 Primary Prevention for interventions that aim to modify behaviour or lifestyle
    • Use 3.3 Nutrition Prevention for studies on the chemopreventative / health protective effect of nutrients, probiotics and nutritional supplements.
  • For studies where nutrition, diet or exercise is used to treat established diseases/conditions. Use 5 Treatment Development for pre-clinical research and 6 Treatment Evaluation for clinical/applied research.
    • Use 5.1 or 6.1 (Pharmaceuticals) for direct use of nutritional supplements as therapeutics
    • Use 5.2 or 6.2 (Cellular / Gene Therapy) for microbiota transplantation therapy
    • Use 5.7 or 6.7 (Physical) for dietics (nutrition and dietary advice) and exercise/physical therapy
    • Use 5.8 or 6.8 (Complementary) for studies of homeopathy