Community Nutrition and Public Health: Surveillance, Policy Instruments and Programme Evaluation
Community nutrition items test whether you can measure a population problem, choose an evidence-based intervention, and prove that it worked. Expect surveillance indicators, Chinese national programmes and policy targets, behaviour-change theory, and evaluation design.
Surveillance and indicators
Core child indicators are stunting (height-for-age), wasting (weight-for-height), underweight (weight-for-age), low birth weight rate, exclusive breastfeeding rate under 6 months, and anaemia prevalence. Adult indicators are overweight/obesity prevalence by Chinese BMI cut-offs, mean salt intake estimated from 24-hour urinary sodium, and mean fruit and vegetable intake. Data sources include the China Nutrition and Health Surveillance, repeated periodically, and the China Health and Nutrition Survey cohort.
Policy and programmes
- The National Nutrition Plan (2017-2030) and Healthy China 2030 set targets for stunting, anaemia, obesity and salt reduction.
- Three reductions, three healths: reduce salt, oil and sugar; promote healthy mouth, healthy weight and healthy bones.
- Universal salt iodisation; iron-fortified soy sauce for anaemia control; Ying Yang Bao, a micronutrient powder providing iron, zinc, vitamin A and other nutrients to infants aged 6-24 months in poorer rural areas.
- School milk and rural compulsory-education student nutrition improvement programmes.
Behaviour-change theory
KAP links knowledge, attitude and practice but assumes knowledge alone changes behaviour. The Health Belief Model weighs perceived susceptibility, severity, benefits and barriers. Social Cognitive Theory contributes self-efficacy and observational learning. The Transtheoretical Model stages people from precontemplation through contemplation, preparation, action and maintenance, so interventions must be stage-matched. PRECEDE-PROCEED structures planning and evaluation.
Evaluation
Distinguish process (was the programme delivered as designed), impact (intermediate change such as knowledge, salt intake or anaemia prevalence) and outcome (long-term change such as stunting or cardiovascular events). Use SMART objectives and, where possible, a comparison group.
Worked example
A county screens 500 children aged 6-24 months and finds 90 with haemoglobin below the age-specific cut-off: prevalence = 90/500 = 18%. A Ying Yang Bao distribution is introduced. The impact indicator is anaemia prevalence at 6 months plus compliance rate; the process indicator is the proportion of eligible children actually receiving sachets monthly. Comparing prevalence before and after without a control group cannot exclude seasonal or economic change, so a neighbouring county without the programme strengthens the design.
Traps that cost marks
Reporting outcome where the question asks for process, or vice versa. Diagnosing iron deficiency from haemoglobin alone, which measures anaemia of any cause. Attributing a fall in prevalence to the programme without a comparison. Quoting spot-urine sodium as equivalent to 24-hour urinary sodium.