Do we really need 2,000 calories a day?
Should we all be eating a dairy product with our meals?
Are five servings of fruit and vegetables really enough?
If you are a health or nutrition specialist of any kind, it is likely that you have already answered these questions with “it depends.”
Bio-individuality in nutrition is an area of study and applied science that helps dig deeper into the “it depends.” It helps to determine how and to what extent different biological and environmental factors impact nutritional needs and how different dietary patterns can meet those needs.
Bio-individuality is a hot topic in nutrition as people from all backgrounds recognize how their unique nutritional and dietary needs differ from those of their friends, family members, and community members.
This article provides you with an introduction to bio-individuality in general, as well as how it relates to nutritional needs and nutrition professions.
What Is Bio-Individuality?
Biological individuality, or bio-individuality, is one of the topics most commonly discussed in a branch of biology called the philosophy of biology. Like most philosophical topics, the exploration of biological individuality begins by asking a question. The primary question in bio-individuality is, “what, in the living world, constitutes a relatively well-defined cohesive unit?”
In other words, we want to understand what constitutes a species. What makes one species separate from another? Then, within that species, what makes one individual different from another?
As you can imagine, there are some wildly interesting and lively discussions on a topic that most of us have probably thought little about. There are entire texts devoted to the topic of bio-individuality, so we could go on and on exploring the philosophy of what makes humans human and what makes our human needs differ from another.
Thomas Pradeu suggests a framework for understanding what makes up a biological individual:
- Physiological individuality – Similarities and differences between basic physiological needs like hydration, food and energy, rest, reproduction, and safety
- Ecological individuality – Similarities and differences between the environment in which individuals live and how they respond to that environment
- Evolutionary individuality – The specific evolutionary traits individuals exhibit as a result of the evolution over hundreds of generations. This can be easily understood when we talk about evolutionary differences between species, but it is also exhibited between individuals of the same species, a topic that is explored in epigenetics.
This framework can be represented as follows:
Source: Pradeu, T. (2016). Organisms or biological individuals? combining physiological and evolutionary individuality. Biology & Philosophy, 31(6), 797–817. https://doi.org/10.1007/s10539-016-9551-1
The topic of bio-individuality might seem complex; there is a reason why people dedicate their entire professional lives to exploring these questions!
For the purpose of this article, however, the most important takeaway is understanding that bio-individuality is the exploration of what makes humans biologically different from other living beings and what makes each individual human biologically different from another human.
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How Does Nutrition Relate to Bio-Individuality?
Bio-individuality in nutrition takes the question a little further; not only does it ask what makes each human different from another, but it asks, “how do nutritional needs differ between humans?”
The diagram presented above helps us to understand what factors might help us to answer this question.
- Physiological needs: People are of different shapes and sizes, and their cells work at different metabolic rates. They also have different activity levels and health statuses.
- Ecological demands: Between the individual and their surroundings, including the climate, the oxygen density, and stressors (pollution, violence, social pressures, etc.)
- Evolutionary differences: There is an entire field of nutrition called nutritional genomics, or nutrigenomics. Based on the study of genetics, “nutrigenomics recognizes that a specific dietary advice that can be beneficial for one individual may be inappropriate, or actually harmful, to another.”
The factors mentioned above are interrelated; for example, ecological demands, like higher temperatures, modify physiological needs, such as the need for protection from heat.
It is important to keep in mind, however, that these bio-individual nutritional demands change over a lifetime as we grow, develop, become ill or get healthy, and move to different environments.
All factors that make us biologically different individuals will not only influence differing needs in energy, but it will also affect our needs for nutrients. Here are some examples:
- People with bigger and taller bodies generally require more energy, macronutrients, and micronutrients to maintain their body weight and healthy function.
- People who live in very cold climates have higher metabolic rates and require a greater intake of fat to provide the body with the building blocks to insulate against the cold.
- People who have experienced food scarcity in their childhood may have a more efficient capacity to store nutrients later in life. This may translate into greater body fat composition.
- People whose ancestors lived several generations in sub-Saharan Africa will likely have different nutritional needs than people whose ancestors lived in northern China for several generations. This is the basis of nutritional genomics.
How Can We Determine People’s Individual Nutritional Needs?
Nutrition experts, including registered dietitians, licensed nutritionists, nutrition coaches, nutritional psychologists, medical nutritionists, and nutritional geneticists, each focus on different aspects of individual nutrition needs and nutritional behaviors.
The specialization of individual nutritional needs of people at risk of or living with illnesses is referred to as clinical nutrition; in most countries, only registered dietitians, licensed nutritionists, and medical nutritionists are permitted to evaluate, diagnose, and treat people based on their individual nutritional needs. Nutrition guidelines are points of reference, but these are generally specialized for individual nutritional needs based on health status, body size, sex, activity level, food availability, and likes and dislikes.
Nutritional psychologists help to understand the impact that nutrition may be having on mental health and vice versa, as well as how to determine and modify eating habits.
Nutrition coaches help to understand the roots of eating, health, and wellness behaviors and support clients in modifying those behaviors for better-sustained health and well-being.
Together, nutrition specialists have the knowledge and tools to better understand a person’s:
- Macronutrient needs
- Micronutrient needs
- Dietary preferences
- Energy needs
- Allergies and sensitivities
Some companies and clinics that offer bio-individual nutrition guidance claim that they can help people determine their individual “ideal dietary pattern.” While there are many factors that can help us understand what foods and lifestyle patterns will help a person feel their best, needs and likes change over time. In this sense, a lens of bio-individuality in nutrition should also recognize and honor an individual’s ancestry, past, present needs, and future goals and needs.
As a health professional, an eye on bio-individuality helps you to provide personalized advice and even fight biases. For example, body size and eating patterns that are considered healthy and normal for one individual may not be healthy for another individual. It recognizes that there are many ways to be healthy, experience health, and exhibit health, just as there are many ways to be unhealthy and experience and exhibit health imbalances.
If We Are All Biologically Individual, Are Food and Nutrition Guidelines Relevant?
Now that you know about bio-individuality in nutrition, you might be questioning whether nutrition guidelines, such as recommended dietary intakes of vitamins, minerals, and macronutrients and 2,000 kcal a day energy recommendations, are relevant.
Food and nutrition guidelines are put in place to help guide entire populations toward healthier eating habits. Most people do not have access to individual nutrition guidance that determines their individual needs and helps set them on a path that optimizes their health and nutrition. In this sense, public health initiatives that provide key messages to the general population about what makes up a healthy diet, what to look out for in food labels, and how much energy intake they should have are important and even life-saving.
Public health messages about nutrition and lifestyle influence populational dietary patterns, which, in turn, impact population death rates (mortality rates).
Appropriate nutrition initiatives recognize that nutrition guidelines are a useful public health strategy, but it is important to recognize bio-individuality in nutrition needs.
Bio-individuality is an area of study that asks the question, what makes individuals of the same species differ from one another?
When applied to nutrition, it helps to explore how those differences in biology impact nutritional and dietary needs.
As a health or nutritional professional, it is useful to recognize how population-based nutritional guidelines are a useful starting point for understanding general nutrition frameworks and needs. At the same time, a focus on bio-individuality can keep us from developing biases in the office by recognizing that individual biological and cultural characteristics will influence differences in dietary patterns, body composition, and health status, among others.