Do people eat more than they used to?

January 14, 2026 •

4 min read

Available calories in the American food supply grew by 18% during the 20th century. This increase in food abundance and accessibility has driven significant shifts in dietary habits, but do people eat more than they used to, and what are the specific factors at play? The answer is a resounding yes, influenced by psychological, societal, and economic changes over the decades.

Quick Summary

An exploration of historical and contemporary food consumption, revealing how societal shifts, food industry practices, and psychological factors have led to increased eating, larger portion sizes, and the prevalence of ultra-processed foods.

Key Points

Increase in Calorie Availability: The global food supply has increased, making more calories available per person than ever before in history.
Larger Portion Sizes: Serving sizes for meals and snacks have steadily increased over the decades, leading people to eat more without realizing it.
Ultra-Processed Food Prevalence: The rise of inexpensive, highly palatable ultra-processed foods designed to be easily overeaten is a major driver of higher calorie intake.
Behavioral and Social Factors: Modern lifestyles, including distracted eating and dining with others (social facilitation), encourage higher food consumption.
Sedentary Lifestyle: Increased automation and less physical activity mean that people are burning fewer calories, exacerbating the effects of increased food intake.
The 'Value for Money' Trap: Economically, larger portions are often marketed as a better value, incentivizing consumers to purchase and consume more food than necessary.
Cultural Dietary Shifts: There has been a significant shift from minimally processed, home-cooked meals toward diets high in sugar, fat, and salt, often consumed away from home.

The Expanding American Diet: A Century of Change

Over the past century, a seismic shift has occurred in our relationship with food. While hunger was the primary concern for most of human history, today, overconsumption is a leading health issue in developed nations. Analysis of historical data shows a clear upward trajectory in the calories available per person, driven by innovations in food production and global supply chains. The average American diet has become increasingly energy-dense, with a greater proportion of calories coming from high-fat, high-sugar, and highly-processed sources.

The Rise of Ultra-Processed Foods

One of the most significant changes in modern diets is the prevalence of ultra-processed foods (UPFs). These products are engineered for maximum palatability and often contain high levels of sugar, fat, and salt, which can bypass the body's natural satiety cues. This makes them easy to overeat, a phenomenon often described as "mindless eating". The food industry spends heavily on marketing to create demand for these foods, contributing to a cycle of overconsumption and weight gain.

The Portion Size Paradox

Another major factor is the increase in portion sizes. Research has consistently shown that when people are offered larger portions, they tend to eat more, often without consciously realizing it. This is driven by several mechanisms:

The 'Appropriateness' Effect: The portion size served acts as an anchor, setting a norm for how much to eat.
The 'Unit Bias' Mechanism: People tend to see one serving (e.g., a single sandwich or bag of chips) as an appropriate amount, regardless of its actual size.
The Visual Cue Effect: Larger plates and containers make portions appear smaller, leading people to serve themselves more.

The impact of supersizing is evident in restaurants and even cookbooks, where recipe portion sizes have grown over time. This normalization of larger quantities has warped our perception of what a normal, healthy amount of food looks like.

Comparison of Food Environment: Then vs. Now


Aspect	Historical Food Environment (e.g., early 20th century)	Modern Food Environment (e.g., 21st century)
Food Availability	Seasonal dependence, local production, fewer choices.	Year-round access to a wide variety of foods from global sources.
Cost of Food	Consumed a much larger percentage of disposable income.	Relatively inexpensive, with budget options often being less healthy.
Processing	Minimally processed or unprocessed foods were the norm.	High prevalence of ultra-processed foods, engineered for taste and shelf life.
Portion Sizes	Generally smaller, reflecting the cost and effort of food production.	Substantially larger portions are the new norm in restaurants and homes.
Eating Habits	Traditional meal times were more common; less snacking.	Chaotic eating patterns, frequent snacking throughout the day.

Psychological and Behavioral Triggers

Beyond the food itself, modern lifestyles provide numerous psychological and behavioral prompts for overeating. Distracted eating, often while watching TV or working, can lead to higher consumption. The social context of eating, known as "social facilitation," also plays a significant role; people tend to eat more when dining with others. Stress and emotional triggers can also drive people to seek out palatable foods, even when not physically hungry. Combined with a more sedentary lifestyle, these behavioral changes create a perfect storm for weight gain.

The Economic Dimension and Sedentary Living

Economic factors have also shaped our eating habits. The increased affordability and abundance of food mean that for the first time in history, a significant portion of the population can easily overeat. The food industry's profit motive drives the production and promotion of inexpensive, high-calorie products, incentivizing overconsumption. Simultaneously, labor-saving technologies and shifts in the built environment have drastically reduced the need for physical activity. The combination of plentiful, cheap calories and less physical exertion makes weight gain almost inevitable for many.

Conclusion

In conclusion, the question "do people eat more than they used to?" is unequivocally answered by analyzing a complex interplay of environmental, economic, and behavioral factors. From larger portion sizes and the rise of ultra-processed foods to societal influences and sedentary lifestyles, modern living has created an environment that encourages excessive calorie consumption. While our physiology is still adapted for a world of food scarcity, our contemporary reality is one of overabundance, a mismatch that has fueled the global rise in obesity and related health issues. Understanding these drivers is the first step toward making conscious changes to regain control over our eating habits and overall health. For further reading on related topics, refer to this review on the complexities of weight gain: Why We Eat Too Much, Have an Easier Time Gaining Than Losing Weight, and How to Counteract It

Frequently Asked Questions

Yes, historical food supply data shows a significant increase in available calories per person over the past century, particularly in developed nations. Furthermore, studies show a rise in obesity rates, indicating that consumed calories exceed energy expenditure.

Larger portion sizes act as a visual cue, normalizing higher levels of consumption. Studies show that when presented with a bigger portion, people eat more without a proportionate increase in feelings of fullness. This effect is often subconscious.

Ultra-processed foods are designed to be hyper-palatable, often with high levels of sugar, fat, and salt. This can override the body's natural satiety signals, making it easy to consume excess calories without feeling full.

Yes, research on 'social facilitation' shows that people tend to eat more food when dining in the presence of others. This effect is linked to meal duration rather than hunger levels.

Modern eating patterns are often chaotic, with frequent snacking throughout the day and into the late evening. In contrast, historical eating patterns were more structured around fewer, more traditional meals.

While it doesn't directly cause people to eat more, a sedentary lifestyle means fewer calories are burned, creating a positive energy balance where increased food intake easily leads to weight gain. This can also diminish the motivation for physical activity.

Yes, food consumption trends vary significantly between countries and are influenced by income, cultural traditions, and geography. While developed countries have seen an increase in calorie availability and UPF consumption, some developing regions may still struggle with low food availability.