Nutritional assessment can be conducted through various methods, each with its strengths and limitations:
1. Dietary Surveys
- Food Frequency Questionnaire (FFQ): A questionnaire that asks how often specific foods are consumed over a given period. It is useful for assessing usual intake but may be subject to recall bias.
- 24-Hour Dietary Recall: Participants recall all foods and beverages consumed in the past 24 hours. This method is detailed but may not reflect usual intake.
- Dietary Records: Participants record their food and beverage intake over a specified period, typically 3-7 days. This method is accurate but can be burdensome for participants.
2. Anthropometric Measurements
- Body Mass Index (BMI): Calculated using weight and height; commonly used to assess underweight, normal weight, overweight, and obesity.
- Waist-to-Hip Ratio: Measures the distribution of body fat and is an indicator of cardiovascular risk.
- Skinfold Thickness: Measures subcutaneous fat to estimate total body fat.
3. Biochemical Assessments
- Blood Tests: Measure levels of nutrients, such as vitamins and minerals, in the blood.
- Urine Tests: Assess the excretion of nutrients and metabolites.
- Hair and Nail Analysis: Used to detect long-term exposure to specific nutrients and contaminants.
4. Clinical Assessments
- Physical Examinations: Conducted by healthcare professionals to identify signs of nutrient deficiencies and excesses.
- Medical History: Collecting information on past medical conditions and dietary habits.
