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Understanding the Basics of Nutrition for a Healthier Life

Updated: May 5


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Thinking of exploring more about Nutrition?

Nutrition touches every aspect of our lives. Nutrition plays a role for maintaining health and well-being, from the foods we eat to how our bodies function. But what is nutrition, and why is it important? Let's start with the basics and look at how diet affects our health, the factors that influence our decisions, and how nutrients benefit the body.

What is Nutrition?

Nutrition is mainly concerned with the impact of food, nutrients, and other substances on the body. It includes a variety of bodily processes like ingestion, digestion, absorption, transport, metabolism, and excretion. Besides the biological processes, nutrition studies the social, economic, and cultural aspects that influence how and what we eat.

Essentially, nutrition is concerned with how living beings connect to the food they eat, specifically how food maintains life, induces development, repairs tissues, and promotes overall health.

Factors That Influence Food Choices



Many factors influence our food choices
Many factors influence our food choices

Have you ever thought about why you prefer some foods over others? Food decisions are rarely based solely on hunger. Several factors affect what we eat, including:

  • Personal preferences (taste and enjoyment)

  • Habits (routine eating behaviors)

  • Ethnic heritage and traditions

  • Social interactions (e.g., eating with friends and family)

  • Availability, convenience, and cost

  • Emotions (stress eating or comfort foods)

  • Values (ethical, religious, or environmental beliefs)

  • Body image and self-perception

  • Health goals (seeking specific health benefits)

  • Age and life stage

Understanding these factors allows us to make more thoughtful and educated eating choices.

What is Health?



When looking at nutrition, it is crucial to understand health. Health is more than simply the absence of disease; it is a condition of total physical, mental, and social well-being. Global institutions such as the World Health Organization emphasize that health is about achieving goals, meeting needs, and adapting to the environment.

Several factors influence health, including money, education, social support, the physical environment, biology and genetics, personal actions, and access to health care services. Nutrition is a significant factor in these influences.






Understanding Nutrients


Nutrients are chemical substances found in foods that our bodies use for various functions.



They are classified into six major classes: 

  1. Carbohydrates

  2. Proteins

  3. Lipids (fats)

  4. Vitamins

  5. Minerals

  6. Water

Nutrients can be grouped into two main categories:

  • Macronutrients (carbohydrates, proteins, fats, and water): needed in large amounts.

  • Micronutrients (vitamins and minerals): needed in smaller amounts.

Although only macronutrients provide calories (energy), micronutrients are essential for regulating body processes and maintaining structure.

Functions of Nutrients

Nutrients perform three primary functions:

  1. Providing energy: Carbohydrates, proteins, and lipids provide the energy required for daily activities.

  2. Building structure: Protein and minerals are important nutrients for the formation of tissues, bones, and cell structures.

  3. Regulating processes: Vitamins, minerals, and water aid to regulate metabolism and maintain homeostasis.

For example, carbohydrates and proteins give approximately 4 kcal per gram, fats provide 9 kcal per gram, and alcohol (while not a food) contributes 7 kcal per gram. 

Measuring Energy in Foods

Scientists use a bomb calorimeter to assess the energy in food by calculating the heat released when it burns. However, because not all dietary energy is entirely digested, the real amounts are corrected using Atwater values, which provide us with useful calorie estimates:

  • Carbohydrate: 4 kcal/g

  • Protein: 4 kcal/g

  • Fat: 9 kcal/g

  • Alcohol: 7 kcal/g

These numbers are used to calculate calorie content in foods and create healthy diets.

Dietary Recommendations

Because individual dietary requirements vary, nutritionists utilize Dietary Reference Intakes



(DRIs), which are a set of scientifically established guidelines created for healthy populations in North America. DRIs aid to guide dietary planning and evaluation.

The key components of DRIs are:

  • Estimated Average Requirement (EAR): Meets the needs of 50% of a specific group.

  • Recommended Dietary Allowance (RDA): Meets the needs of 97.5% of the group.

  • Adequate Intake (AI): Set when there isn't enough data to establish an EAR.

  • Tolerable Upper Intake Level (UL): The maximum daily intake unlikely to cause harm.

Acceptable Macronutrient Distribution Ranges (AMDRs) also specify the percentage of total energy that each macronutrient should account for:

  • Carbohydrates: 45–65% of daily energy

  • Fat: 20–35% of daily energy

  • Protein: 10–35% of daily energy

Following these standards encourages a healthy diet and reduces the risk of chronic disease.




The Importance of Fiber

Fiber is a vital part of a healthy diet, aiding digestion, lowering cholesterol, and increasing satiety. Fiber recommendations vary by age and gender, with adults being advised to ingest between 25 and 38 grams per day. Whole grains, legumes, fruits, and vegetables are great sources.

Health Promotion Through Nutrition

Nutrition is strongly related to health promotion, which encourages people to take responsibility for their health by making informed lifestyle choices. Resources like Canada's Food Guide provide easy, evidence-based suggestions for healthy eating, such as:

  • Emphasizing plant-based foods

  • Choosing whole grains

  • Limiting highly processed foods

  • Staying hydrated with water

Conclusion

Nutrition is more than just eating; it is a comprehensive science that links food, health, and well-being. Understanding the fundamentals of nutrition, energy requirements, and dietary recommendations allows us to make better choices that promote lifetime health. Whether you want to improve your own diet or pursue a profession in nutrition, having a solid foundation in these principles is a powerful first step.



Reference:


Pacheco, Craig. (2023). What is Nutrition' [Lecture notes]. Toronto Metropolitan University.


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