The right formula. The universal eating plan that will improve our health, boost our energy, and help us feel better in our bodies. Yet many people eventually encounter a confusing reality: a diet that works wonderfully for one person may not work at all for another. Someone may feel energetic and balanced on a low-carbohydrate diet, while another person feels exhausted and irritable. One individual thrives on a plant-based diet, while someone else experiences constant hunger and low energy. These differences are often explained by discipline, motivation, or how strictly someone follows a plan. But decades ago, one scientist offered a different explanation — human bodies are simply not the same.
Biochemist Roger J. Williams, in his remarkable book Biochemical Individuality, introduced an idea that today forms the foundation of modern personalized nutrition and medicine: every human being is biologically unique.
As he wrote:
“Every individual is a unique biochemical entity.”
This concept forms the basis of what we now call bioindividual nutrition.
The Science Behind Individuality
Roger J. Williams was not a diet promoter or author of trendy eating plans. He was a respected scientist known for discovering vitamin B5 (pantothenic acid) — a nutrient essential for energy metabolism. During his research, Williams began noticing something that would fundamentally change how we think about nutrition. At that time, science generally assumed that human bodies functioned in mostly the same way. But when Williams began examining human anatomy and biochemistry more closely, he discovered striking differences. The size and shape of internal organs — such as the stomach, liver, and pancreas — can vary significantly from one person to another. These variations are not merely anatomical curiosities. They influence how the body digests food, absorbs nutrients, and produces energy.
Williams summarized his observations with a bold statement:
“There are as many biochemical types of human beings as there are human beings.”
In other words, although we share the same basic human physiology, the details of how our bodies function are unique for each individual.
Why Universal Diets Often Fail
If our bodies are so different, it makes sense that our responses to food would also vary. Yet much of nutrition advice is built around universal models — a single dietary pattern assumed to work for most people.
Many individuals, however, have experienced something that challenges this idea.
You may have followed a popular diet that worked remarkably well for friends or colleagues, but produced little improvement for you — or even made you feel worse. Perhaps you experienced fatigue, digestive discomfort, or unstable energy levels. According to Williams, this outcome should not be surprising.
Our nutritional needs are shaped by many factors: metabolism, enzyme activity, hormonal balance, digestive capacity, and even the structure of our internal organs. For this reason, he emphasized that nutritional needs can vary enormously between individuals. When these differences are ignored, people often find themselves caught in a cycle of trying one diet after another without discovering a way of eating that truly supports their health.
Modern Science Is Confirming These Ideas
When Biochemical Individuality was first published in 1956, Williams’ ideas were considered revolutionary. Today, however, multiple scientific fields are confirming his observations.
Nutrigenomics
Nutrigenomics studies how genetic differences influence our response to food. Research shows that genes can affect how we metabolize fats, carbohydrates, and certain vitamins.
The Gut Microbiome
The trillions of microorganisms living in our digestive system play a major role in health. Each person’s microbiome is unique, influencing how foods are digested and how the body responds to nutrients.
Individual Blood Sugar Responses
Recent studies demonstrate that two people can have completely different blood sugar responses to the same food. A meal that keeps one person’s glucose stable may cause sharp spikes and crashes in another. All of these discoveries support Williams’ central insight: nutrition is not universal.
What Bioindividual Nutrition Looks Like in Real Life
In practice, bioindividual nutrition means accepting that different people thrive on different dietary patterns.
One person may feel their best after a breakfast rich in protein and healthy fats, while another may prefer oatmeal with fruit and nuts.
Some individuals tolerate dairy without any issues, while others experience bloating or inflammatory reactions. For certain people, moderate carbohydrate intake supports stable energy, while for others it leads to fatigue and intense hunger. These differences do not mean that one food is “good” and another is “bad.” They simply reflect the different ways our bodies respond to food.
Learning to Listen to the Body
One of the most valuable principles of bioindividual nutrition is learning to pay attention to the body’s signals. Instead of forcing ourselves to follow a predetermined diet, we can observe how we feel after eating certain foods and patterns of meals.
Helpful signals include: energy levels throughout the day, digestive comfort, sleep quality mood and mental clarity signs of inflammation.
These signals help us gradually build a way of eating that supports our unique biology.
A More Compassionate Approach to Nutrition
Bioindividual nutrition also offers something deeply important — a more compassionate perspective toward ourselves. When a diet fails, many people blame themselves. They assume they lacked discipline or did not follow the plan strictly enough. But if our bodies are biochemically different, then a diet that doesn’t work for us is not necessarily a personal failure. It may simply mean that the plan was not suited to our physiology. This understanding can replace guilt with curiosity — curiosity about what truly helps our bodies function at their best.
The Future of Nutrition Is Personal
More than sixty years after the publication of Biochemical Individuality, Roger J. Williams’ ideas remain strikingly relevant. They remind us that the human body is a complex and unique system. Health cannot always be achieved through universal rules or popular diets.
As Williams wrote:
“Each of us has a unique nutritional pattern that cannot be duplicated by anyone else.” Perhaps the future of nutrition is not about discovering one perfect diet for everyone. Perhaps it lies in something much simpler — understanding our own bodies and nourishing them in ways that respect their individuality.
