Type 2 Diabetes and Blood Sugar Control: Lessons from Hummingbirds

Type 2 diabetes has become one of the defining health challenges of the modern world. Hundreds of millions of people now live with the disease, and the number continues to climb despite decades of research, new medications, improved glucose monitoring, and an endless stream of dietary advice. Blood sugar has become one of the most familiar health numbers in medicine and among the general population.

Today, glucose is a widely vilified nutrient and at the same time a central nutrient in emergency medicine, where it is administered directly into the bloodstream as intravenous dextrose when life hangs in the balance. The question is, why does glucose regulation seem to fail so often in modern society? And why do the so-called glucose spikes after a meal evoke the image of a disease-causing nutrient, even among seemingly healthy individuals?

Nature often provides clues that medicine alone cannot. Among the most remarkable examples is the hummingbird, and few animals consume as much sugar relative to their body size. A hummingbird spends much of its day drinking nectar, a sugar-rich liquid without the fiber that ordinarily accompanies sugars in intact plant foods. During periods of intense activity or migration, it may consume an amount of nectar approaching its own body weight in a single day. If sugar itself were sufficient to explain the diabetic state, what are we supposed to make of an animal practically bathing its metabolism in sugar while flying around like a biological furnace? Hummingbirds should be among the sickest animals on Earth. They are not! Instead, they are among nature’s greatest metabolic successes.

The explanation is not that hummingbirds possess magical protection against sugar.  Rather, they demonstrate an important biological principle that reminds us that time matters even in the presence of high concentrations. In other words, the sugar they consume does not remain in the bloodstream for long. Their wings beat around 50–80 times every second, their heart rate may exceed 1,000 beats per minute during flight, and oxygen delivery is exceptional. Their muscles can therefore extract glucose from the blood rapidly and oxidize it at extraordinary rates. Hummingbird metabolism is not simply characterized by high sugar intake, but by extraordinarily high energy processing power.

The point is not that humans should imitate the hummingbird’s extraordinary physical prowess. Birds and humans are very different organisms with different physiologies, body sizes, and metabolic demands. The comparative insight is that nutrients can only be understood in the context of the system that handles them. A nutrient entering the body tells only part of the story, but equally important is what happens after it arrives.

This becomes more interesting when we examine human history. Undoubtedly, humans have consumed an astonishing variety of diets. Some populations depended heavily on roots, tubers, and grains, supplemented by locally available fruits. Others obtained much of their energy from fish and animal foods. The proportions differed widely from one environment to another because different climates supported different plant and animal foods. Remarkably, before modernization, type 2 diabetes appears to have been uncommon across many traditional societies despite these dietary differences.

The shared characteristic of traditional societies was the way of life and not some kind of universal menu. Food was generally acquired through physical effort, and walking was transportation, not exercise advice. Carrying, climbing, digging, gathering, hunting, farming, and other forms of daily work demanded continual movement. Through different local foods, nutrients entered the body, but they did not simply remain there. They were continuously transported, transformed, and used. As muscles repeatedly removed nutrients from the bloodstream, circulation adapted to regular activity, and metabolism operated within an environment of persistent biological flow.

Given that biological outcomes are rarely explained by a single variable, many other factors such as food availability, life expectancy, and genetics may have contributed to the rarity of type 2 diabetes in traditional societies. However, the remarkable consistency of regular physical activity across traditional populations represents one of the major differences separating them from modern industrial societies.

For much of the world’s population, calories are available with minimal physical effort, and transportation has replaced walking. Machines have replaced much of manual labor, while screen-based work now occupies hours that were once spent moving. This remarkable success of technology has reduced the physical demands of daily life while preserving, and often increasing, access to food. The result is not merely greater energy intake but a growing mismatch between nutrient delivery and the body’s capacity to process those nutrients.

Therefore, blood sugar should not by itself be mistaken for the disease but may instead provide one visible sign of a broader metabolic problem. Glucose is one of the easiest molecules to measure, which is why it dominates both medical practice and public discussion, but it is only one part of a much larger system of energy handling. Fatty acids, amino acids, triglycerides, oxygen delivery, mitochondrial function, hormonal signaling, circulation, and muscle activity all participate in determining whether nutrients continue moving productively through the body or begin accumulating where they should not.

This is why focusing exclusively on sugar can sometimes become misleading. Lowering blood glucose is often essential, particularly for people living with diabetes. But lowering the number does not completely answer the biological question. Nature appears less concerned with keeping glucose absent than with keeping glucose moving. Across countless species, health depends not simply on the presence of nutrients but on the remarkable ability to transport, distribute, transform, and utilize them continuously.

Comparatively, hummingbirds demonstrate that metabolism is not a static storage system but a dynamic flow system. When this flow remains coordinated, nutrients support biological function rather than becoming sources of metabolic congestion. One reason the diabetes epidemic has proven so difficult to solve may be that much of the conversation has centered on the amount and types of carbohydrates and sugars entering the body. However, the physiological question is, how well does the organism handle the nutrients that enter it? Across biology, nutrients and movement have always existed together. Glucose has never functioned in isolation from the systems that transport and use it. As modern life gradually separated abundant nutrition from abundant movement, it may also have separated nutrient delivery from nutrient handling.

Understanding diabetes may therefore require looking beyond blood sugar alone. Blood glucose remains an important marker, but it is only one window into a much larger biological landscape. The deeper concern is not the handling of one nutrient alone, but the continuous movement and processing of all nutrients through living systems. In this sense, the hummingbird is not simply a fascinating bird but a reminder that throughout nature, health depends not merely on what enters the body, but on what the body is able to do with it.

Mukaila Kareem is a doctor of physiotherapy and founder of metabolichealthliteracy.com