Define and Differentiate Between:
a) Dietary History
Definition: Dietary history is a method used to assess an individual’s usual food intake over a long period. It provides information about eating habits, portion sizes, meal patterns, and nutrient intake. This method is useful in both clinical and research settings to analyze nutritional status.
Advantages:
- Provides long-term dietary patterns
- Helps in detecting nutrient deficiencies
Limitations:
- Depends on memory and honesty of the person
- Time-consuming and may be inaccurate
b) Negative Secular Trend and Positive Secular Trend
Definition: Secular trends refer to long-term changes in growth patterns over generations due to environmental improvements or deterioration.
Positive Secular Trend:
- Refers to an increase in average height, weight, or earlier puberty across generations
- Caused by better nutrition, healthcare, and living standards
Negative Secular Trend:
- Indicates a decline in growth and development metrics
- Linked to poverty, malnutrition, and poor living conditions
Difference:
While positive trends show societal progress in health and nutrition, negative trends indicate worsening environmental or social conditions affecting growth.
c) Distance Curve and Velocity Curve
These are graphical tools used to study growth over time.
Distance Curve:
- Shows cumulative growth over time (e.g., total height at various ages)
- Helps track overall development from birth to adulthood
Velocity Curve:
- Shows the rate of growth (e.g., cm/year)
- Highlights growth spurts, especially during puberty
Difference:
The distance curve shows the total amount of growth, while the velocity curve shows how fast the growth is happening at each stage.