Nutritional Value of Food: An Overview

The nutritional value of a food is evaluated based on three main factors:

1. Nutrient Composition: This includes macronutrients (carbohydrates, protein, fats) and micronutrients (vitamins, minerals) present in the food.

2. Biological Value: This determines the digestibility, absorption, metabolism, and utilization of nutrients by the body.

3. Safety Level: This ensures that the food does not contain harmful substances, disease-causing bacteria, or allergenic ingredients.

Biological Value of Nutrients:

– Digestibility: The breakdown of complex nutrients into simpler forms that are easily absorbed.

– Absorption Rate: The amount of nutrients absorbed into the bloodstream from the intestines.

– Metabolism: The process of converting nutrients into energy or essential compounds for the body.

– Utilization: The efficiency of using nutrients in biological processes.

Factors Affecting Absorption:

– Absorption Enhancers: These enhance the absorption of nutrients from the intestines into the bloodstream. Example: Vitamin C assists in the absorption of iron and zinc.

– Absorption Inhibitors: These limit the absorption of nutrients from the intestines into the bloodstream. Example: Phytate in grains restricts iron absorption.

– Absorption Competitors: These compete with other nutrients for absorption through transport proteins. Example: Copper and zinc compete for absorption.

– Co-absorption: Nutrients absorbed simultaneously into the bloodstream due to their binding together. Example: Glucose is a co-absorbent of Sodium.

Empty Calorie Foods:

– These foods are rich in carbohydrates and fats but lack essential micronutrients.

– Harmful to health:

– Depletion of body reserves.

– Nutrient metabolism disorders.

Dietary Recommendations:

– Animal Protein: Should constitute 30-50% of the total protein requirement.

– Added Sugar: Should be limited to under 10% of total energy intake (approximately 50g).

– Ideally, below 5% of total energy for optimal health benefits.

– Fat:

– Saturated fat: Below 10% of total energy.

– Trans fat: Below 1% of total energy.

– Cholesterol: Below 300mg per day.

Food Characteristics:

– Carbohydrate-rich Foods:

– Vitamins essential for carbohydrate metabolism are abundant in the husk.

– Easily lost during milling, soaking, and washing.

– Protein-rich Foods:

– Not broken down by high temperatures, so they don’t change significantly during cooking.

– Fat-rich Foods:

– Heart-healthy fats are those that remain liquid at refrigerator temperatures.

– Easily oxidize and form toxic substances (acrolein, peroxide…), so they need to be stored in cool, dark conditions.

– Fiber and Water-soluble Vitamin-rich Foods:

– Easily washed away and vaporized during cooking.

– Cook quickly and eat immediately to preserve maximum nutritional value.

Food Additives:

– These are substances with no nutritional value added to food to enhance appearance, extend shelf life, or improve desired qualities.

– They are not considered food or food components.

Note:

– Choose a variety of foods to provide the body with all the necessary nutrients.

– Pay attention to food preparation and storage methods to preserve nutritional value.

– Limit processed foods and empty calorie foods.

– Consult a nutritionist to create a diet plan tailored to your body’s needs.