Understanding Nutrition: What's the Least Nutritious Food?

October 20, 2025 •

4 min read

According to the American Heart Association, highly-processed items like snack foods and fast food are among the most common unhealthy foods consumed. The least nutritious foods are often those providing 'empty calories'—energy primarily from added sugars and solid fats, with very little beneficial nutrition.

Quick Summary

This guide examines the concept of 'empty calories' and ultra-processed foods, exploring why they offer minimal nutritional value while impacting health negatively. It provides common examples and practical swaps for a more nutrient-dense diet.

Key Points

Empty Calories Defined: The least nutritious foods are primarily sources of 'empty calories', meaning they provide energy with minimal vitamins, minerals, or fiber.
Ultra-Processing is a Key Factor: Many empty-calorie foods are ultra-processed, made with industrial ingredients not typically used in home cooking, and contain low nutritional value.
Top Offenders: Examples of least nutritious foods include sugary drinks, commercially baked goods, processed meats, and salty snack foods.
Health Impacts: High consumption of empty-calorie foods is linked to weight gain, chronic diseases like diabetes and heart disease, and nutrient deficiencies.
The Best Strategy: Prioritizing nutrient-dense whole foods and making smart swaps is a more effective strategy for improving diet quality than simply banning specific items.

What Defines 'Least Nutritious' Food?

When discussing what makes a food the 'least nutritious,' experts often use the term 'empty calories'. This refers to foods and beverages that provide calories, but little to no vitamins, minerals, protein, or fiber. These foods are typically high in added sugars, solid fats, and sodium, which are associated with negative health outcomes when consumed excessively.

The Rise of Ultra-Processed Foods

Many of the least nutritious items fall under the category of ultra-processed foods (UPFs). These are industrially manufactured products containing ingredients rarely used in home cooking, such as emulsifiers, flavour enhancers, and artificial sweeteners. Research indicates a strong correlation between high consumption of UPFs and poor health. For instance, a meta-analysis showed that higher UPF intake negatively correlated with a reduction in essential nutrients like fiber, protein, and micronutrients.

Categories of Empty-Calorie Foods

Several food categories are notorious for their low nutritional density and high 'empty calorie' content:

Sugary Drinks: Soda, sweetened iced teas, fruit-flavored beverages, and energy drinks are among the primary sources of added sugar in many diets. They provide a large number of calories with no nutritional benefit.
Baked Goods and Sweets: Commercial cookies, cakes, donuts, and pastries are packed with refined flour, added sugars, and unhealthy fats. The combination provides a rapid spike in blood sugar followed by a crash, offering little to no satiety.
Processed Meats: Items like bacon, hot dogs, and salami are high in salt, saturated fat, and calories. The World Health Organization has classified processed meats as carcinogens, linking them to an increased risk of certain cancers.
Salty Snacks: Potato chips, some pretzels, and packaged crackers are typically deep-fried or baked with refined ingredients and high levels of sodium. They lack significant fiber and protein, contributing to high caloric intake without filling you up.
Fast Food and Fried Items: French fries and deep-fried fast-food products are cooked in refined oils and loaded with saturated fats and sodium. Regular consumption is linked to obesity and cardiovascular disease.
Certain Refined Grains: While not entirely without nutrients, refined white bread and white rice have been stripped of most fiber and vitamins during processing, making them less nutritious than their whole-grain counterparts.

The Health Implications of a Low-Nutrient Diet

Regularly consuming foods with little nutritional value displaces the intake of nutrient-dense options like fruits, vegetables, whole grains, and lean proteins. This can lead to a host of health problems:

Weight Gain and Obesity: Empty-calorie foods are often highly palatable and easy to overeat, leading to an excess calorie intake that the body stores as fat.
Increased Risk of Chronic Diseases: Diets high in saturated fat, sugar, and sodium are major risk factors for conditions such as type 2 diabetes, heart disease, and high blood pressure.
Nutrient Deficiencies: By filling up on empty calories, individuals may not get enough essential vitamins and minerals, which are crucial for overall bodily function.

Comparison: Least Nutritious vs. Nutrient-Dense

This table highlights the stark differences between some common empty-calorie foods and their healthier, nutrient-dense alternatives.


Feature	Least Nutritious (Empty Calories)	Nutrient-Dense Food	Comparison
Energy Source	Primarily added sugars and solid fats.	Complex carbohydrates, healthy fats, and protein.
Micronutrients	Very low in vitamins and minerals.	High levels of vitamins, minerals, and antioxidants.
Fiber Content	Minimal to none, promoting rapid blood sugar spikes.	High, aiding digestion and promoting satiety.
Ingredients	Long lists of additives, preservatives, and artificial ingredients.	Whole, minimally processed, recognizable ingredients.
Example	Soda, packaged cookies, potato chips.	Plain yogurt with fruit, roasted chickpeas, nuts and seeds.

Making Smarter Dietary Choices

Instead of completely eliminating foods, the focus should be on balance and smart swaps. Here are some strategies:

Read Food Labels: Pay close attention to added sugars, saturated fats, and sodium levels.
Prioritize Whole Foods: Build meals around minimally processed foods like fruits, vegetables, whole grains, and lean protein sources.
Prepare Meals at Home: Cooking allows for greater control over ingredients, enabling you to reduce unhealthy additives and excess salt.
Make Smart Swaps: Opt for whole-grain bread over white bread, choose plain yogurt and add your own fruit instead of flavored varieties, and bake your own treats to control sugar content.

Conclusion

While a definitive single answer to What's the least nutritious food? is complex, the collective evidence points to ultra-processed and empty-calorie foods. These items, characterized by high levels of added sugar, salt, and unhealthy fats and a lack of essential nutrients, are the primary culprits. Focusing on a diet rich in nutrient-dense whole foods is the most effective strategy for improving overall health and reducing the risks associated with a low-nutrient intake.

For more insight into diet and nutrition, consider consulting trusted resources like the British Heart Foundation.

Frequently Asked Questions

Empty-calorie foods provide energy but few or no essential nutrients, while nutrient-dense foods offer a high amount of vitamins, minerals, and other beneficial compounds for the calories they contain.

No, not all processed foods are low in nutrition. Some processed items, like whole-grain bread or canned beans, can have nutritional value. Ultra-processed foods, which contain many additives and little whole food, are the most concerning.

Sugary drinks are a major source of empty calories because they are high in added sugars but contain virtually no beneficial nutrients. They contribute to weight gain, blood sugar spikes, and an increased risk of chronic diseases.

While some fast food may contain some nutrients, much of it is ultra-processed and high in saturated fat, sodium, and added sugar, classifying it largely as empty calories. Better choices exist, such as opting for grilled rather than fried items.

Yes, unlike fresh cheese, processed cheese slices and spreads often contain added saturated fats, sodium, and artificial ingredients that reduce their overall nutritional value.

Ultra-processed foods are designed to be highly palatable. They are formulated with specific combinations of sugar, fat, and salt to stimulate the brain's reward centers, which can lead to overeating.

Yes, alcohol is considered a source of empty calories because it provides energy without significant nutritional value. Excessive intake can contribute to weight gain and other health problems.