The review, led by Jennie Brand-Miller and colleagues, examines how changes in brain size, body size, activity levels and metabolic requirements may have shaped the diets of early hominins. Their modeling suggests that naturally occurring sugars could have supplied approximately 20 to 35 percent of total dietary energy during substantial periods of human evolution. These carbohydrates would have been available from foods such as ripe fruits, honey and possibly other plant sources. The researchers argue that this energy could have been especially valuable because the human brain consumes a disproportionately large amount of glucose compared with its size.

The brain is a metabolically expensive organ. Although it accounts for only a small fraction of total body mass, it requires a continuous supply of energy to maintain electrical signaling, synthesize neurotransmitters and support the activity of billions of neurons. Glucose is a major fuel for the brain under ordinary dietary conditions, while other tissues, including red blood cells, rely heavily or exclusively on glucose. As hominin brains increased in size and bodies became more active, the demand for rapidly available energy would also have risen. The researchers propose that carbohydrate-rich foods helped meet this demand alongside the nutrients supplied by animal foods.

The findings do not reject the importance of meat, fish or other animal products. Instead, they present human evolution as the result of a broader dietary strategy. Animal foods provided concentrated protein and fats and may have supported changes in anatomy, including smaller teeth, reduced jaw size and a shorter digestive tract. These adaptations are often interpreted as evidence that meat became increasingly central to the human diet. However, the new review argues that the evolutionary advantages associated with animal foods may have developed in parallel with an expanding reliance on carbohydrate sources.

Natural sweetness may also have influenced food choice and foraging behavior. Sugars provide immediate energy, and humans possess specialized sensory and metabolic systems that detect and process sweet foods. The strong preference for sweetness seen in modern humans could reflect, in part, an ancient attraction to energy-dense resources. Fruit and honey are not uniformly available, however. Their abundance changes with season, rainfall, temperature and habitat conditions. The researchers suggest that these fluctuations may have encouraged early humans to develop larger ranging patterns, more flexible diets and improved memory for the location and timing of valuable food sources.

Honey may have been particularly significant because it combines highly concentrated sugars with relatively little structural material. Although direct evidence for honey consumption by early hominins is limited, the potential energetic value of honey makes it an important component of the researchers’ evolutionary model. Accessing it would have required practical skills and, in some environments, cooperation or the use of tools. Fruit, meanwhile, could have supplied sugars, water and micronutrients, although its availability and nutritional composition would have varied widely among ecosystems and seasons.

The review also highlights the likely importance of cooking. Before cooking became widespread, much of the carbohydrate available to hominins may have come from raw fruits and other naturally sweet foods. Cooking later increased access to starch by softening plant tissues, gelatinizing starch granules and making certain underground storage organs and seeds easier to digest. It also reduced the time and energy required to chew and process these foods. By improving the digestibility of starch, cooking could have expanded the carbohydrate supply available to populations whose brains and bodies had increasingly high energy requirements.

The researchers connect these dietary changes to human physiology and genetics. Modern humans possess adaptations related to glucose transport, insulin regulation and starch digestion, including variation in the number of copies of the salivary amylase gene, which helps begin starch breakdown in the mouth. Such traits do not provide a simple record of ancient diets, but they indicate that carbohydrate metabolism has been important in human biology for a long time. The review combines these biological clues with estimates of energy expenditure and body composition to build a model of how sugars and starches may have contributed to human evolution.

The study also raises questions about the relationship between ancient dietary flexibility and modern health. Human metabolic systems evolved in environments where sweet foods were often seasonal, difficult to obtain or physically demanding to process. Today, refined sugars and highly processed starches are widely available in concentrated forms, creating nutritional conditions that differ sharply from those experienced by most of our ancestors. The evolutionary importance of carbohydrates does not mean that all modern sources of sugar are equivalent to fruit, honey or cooked plant foods. Instead, the authors emphasize that the type, concentration and availability of carbohydrates matter when considering their effects on health.

By placing sugars and starches alongside animal foods in the evolutionary record, the review offers a more complex explanation for the emergence of the human brain. It suggests that human evolution was powered by dietary diversity rather than by a single transformative food. Meat and other animal products may have supplied essential nutrients, while naturally sweet foods and later cooked starches helped provide the glucose required by an energetically demanding brain. The researchers’ estimate that natural sugars supplied roughly one-fifth to one-third of dietary energy during much of human evolution adds a striking dimension to the familiar story of how humans became human: the path to a larger brain may have been fueled not only by hunting, but also by the pursuit of sweetness.

Subject of Research: The role of sugars, carbohydrates and starches in human brain development and evolution

Article Title: Sweet: Sugars, diet, and human evolution—an analytical review

News Publication Date: 6-Aug-2026

Web References: https://doi.org/10.1126/science.aed8437

References: Brand-Miller et al., Science, “Sweet: Sugars, diet, and human evolution—an analytical review”

Keywords: human evolution, brain evolution, carbohydrates, sugars, starch, fruit, honey, cooking, diet, glucose metabolism, neuroscience, anthropology, nutrition, Science

The study presents an intricate narrative that examines the diets of early hominins, suggesting that their hunting strategies were not merely a means of survival but also reflected a dynamic interaction with their environment. The rich archaeological deposits at the Loiyangalani site provide insights into the types of game hunted, the tools employed, and the social structures that may have governed these activities. Masele’s work emphasizes the significance of animal remains found at the site, highlighting a diverse diet that included large herbivores such as antelope and smaller mammals.

Masele’s meticulous examination of faunal remains reveals not just the preferred species but also the seasonal patterns of hunting. This research indicates that Middle Stone Age hominins were highly attuned to their surroundings, possessing a nuanced understanding of animal behavior, migration patterns, and environmental fluctuations. Such adaptability speaks volumes about the cognitive capabilities of our ancestors and their ability to thrive in diverse habitats.

Additionally, the analysis of stone tools found at the site forms a crucial component of Masele’s research. These tools reveal a sophisticated technological repertoire, illustrating the evolution of hunting techniques over time. The presence of both sharp and blunt tools suggests a complex array of strategies used in both the processing of meat and the butchery of animals. This diversification in tool-making reflects a broader evolutionary trend toward enhancing efficiency and effectiveness in resource acquisition.

Moreover, Masele’s findings challenge the previously held notion that meat consumption by early hominins was primarily opportunistic. The evidence suggests that hunting was a deliberate activity, potentially indicating social cooperation and planning among groups. Such insights invite us to reconsider the social dynamics of early human communities, highlighting the roles of collaboration and knowledge-sharing in successful hunting endeavors.

The environmental context of the Loiyangalani site also plays a vital role in Masele’s research. The Serengeti ecosystem, with its varied landscapes and species, provided a rich backdrop for early hominin life. The climatic shifts during the Middle Stone Age significantly impacted both flora and fauna, shaping the strategies that hominins employed to secure food. Understanding these environmental relationships could lead to a better grasp of how early humans adapted to challenges such as climate change and habitat alterations.

This research is timely, especially as contemporary societies grapple with issues of sustainability and food security. The lessons derived from our ancestors’ resilience and adaptability may offer valuable insights into modern hunting practices and the broader implications of human interaction with nature. By studying the past, we glean knowledge that can inform present-day conservation efforts and wildlife management strategies.

Furthermore, the study underscores the importance of interdisciplinary research in archaeology. By incorporating insights from ecology, anthropology, and nutrition, Masele’s work illustrates the potential for a more integrated understanding of human evolution. This approach not only enriches archaeological methodologies but also enhances the narratives we develop around our origins and survival strategies.

An additional layer of significance to Masele’s research is the socio-cultural aspect of hunting and meat consumption. The findings suggest that food-sharing practices may have been a foundational element of social bonds among Middle Stone Age communities. Sharing meat resources likely fostered social cohesion and established roles within groups, paving the way for more complex social structures.

The implications of this research extend beyond the confines of the Loiyangalani site. They resonate with broader themes in the study of human evolution, particularly the ways in which our ancestors interacted with and transformed their environments. As the debate continues around the evolution of human culture and behavior, Masele’s work provides critical evidence that could provoke re-evaluations of existing theories concerning the origins of social and dietary complexities.

Despite the compelling nature of the findings, challenges remain for future investigations. The need to conduct further excavations at the Loiyangalani site is imperative to uncover additional layers of evidence that could shed light on other aspects of Middle Stone Age life. Such efforts could solidify the link between dietary practices and social structure, enriching our historical narrative.

In summary, F. Masele’s research on hunting and meat-eating in the Middle Stone Age at the Loiyangalani site is a vital contribution to our understanding of early hominins. By combining archaeological data with ecological awareness, this study not only enhances our knowledge of human dietary evolution but also invites broader reflections on adaptation, survival, and social cohesion throughout human history. The lessons learned from our ancestors hold profound implications for the future, urging us to learn from the past as we confront contemporary challenges relating to food systems and environmental sustainability.

As we move forward, the dialogue sparked by this research promises to invigorate the field of archaeology and ignite interest in the ongoing legacy of human evolution. The journey through the Middle Stone Age is far from over, and the revelations unearthed at the Loiyangalani site stand as a testament to the untold stories that continue to shape our understanding of what it means to be human.

Subject of Research: Hunting and meat-eating by Middle Stone Age hominins at the Loiyangalani site in Serengeti National Park, Tanzania.

Article Title: On Hunting and Meat-eating by Middle Stone Age Hominins at Loiyangalani Site in Serengeti National Park, Tanzania.

Article References: Masele, F. On Hunting and Meat-eating by Middle Stone Age Hominins at Loiyangalani Site in Serengeti National Park, Tanzania. Afr Archaeol Rev 42, 73–94 (2025). https://doi.org/10.1007/s10437-024-09607-3

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s10437-024-09607-3

Keywords: Middle Stone Age, hominins, hunting, meat-eating, Loiyangalani, Serengeti, archaeology, evolution, social dynamics, food security.