A BBC Morning Live investigation aired in late 2023 has uncovered that several major fast-food chains are significantly underreporting calorie counts on their menus — with some items found to contain up to 31% more calories than advertised.
The findings suggest widespread inaccuracies in calorie labeling, raising concerns for anyone trying to make informed dietary choices. As fast-food chains operate globally and use similar preparation and labeling systems, these discrepancies may impact consumers well beyond the UK, including in the United States, where calorie transparency is also a public health priority.
Jump to:
- Popular menu items tested showed alarming differences
- Inconsistencies vary by location
- Experts explain why menu calorie counts can be misleading
- Natural ingredients — and human error — add complexity
- Calorie labeling was introduced to guide healthier choices
- Fast-food companies respond to the findings
- Calorie counts matter — but they’re only part of the picture
- What consumers should keep in mind
Food scientists from the University of Greenwich analyzed the actual calorie content of several popular fast-food menu items using professional calorimetry equipment — a far more precise method than the software tools most restaurants rely on.
The following menu items were tested:
- McDonald’s Bacon Double Cheeseburger (listed at 495 calories)
- Greggs’ Sausage, Bean and Cheese Melt (listed at 454 calories)
- KFC’s Zinger Supercharger Tower Burger (listed at 650 calories)
Each item was found to contain significantly more calories than claimed on menus:
- McDonald’s burger tested 31% higher than stated
- KFC’s chicken sandwich was 28% higher
- Greggs’ pastry showed a 24% increase
These figures go well beyond the 20% variance typically allowed by food regulatory guidelines in both the UK and US, highlighting a major breakdown in consistency and accuracy.
Inconsistencies vary by location
The research team went further, purchasing the same menu items from three different locations of each chain to test for branch-level consistency.
The results revealed striking differences even within the same chain:
- One branch’s bacon cheeseburger was 31% above the listed calorie count, while the other two were closer to the stated value.
- Greggs’ melt varied, with one sample testing 24% higher, while others stayed within an acceptable range.
- For KFC’s burger, two branches exceeded the listed calories by 30%, while one was 9% lower than advertised.
This variability suggests that staff preparation, ingredient variations, and portion control are all contributing to calorie discrepancies that consumers are unlikely to detect — but that can significantly affect dietary intake.
Dr. Nazanin Zand, professor of food science and nutrition and lead researcher on the investigation, explained that most fast-food restaurants use nutritional software and standard recipes to generate calorie counts.
However, she noted that this method has serious limitations.
“In practice, chefs don’t always follow exact measurements,” Zand said. “The software often doesn’t fully account for real-world factors like cooking technique, ingredient variation, or portioning.”
Dr. Elena Lopez, her colleague at the University of Greenwich, conducted the calorimetry analysis. The results confirmed that even with strict guidelines in place, the food served to customers can differ substantially from what the menu claims.
Natural ingredients — and human error — add complexity
Registered dietitian Claire Thornton-Wood added that variations in natural ingredients play a significant role.
“A burger might look the same every time, but it could come from a slightly fattier part of the animal,” she said. “That alone can bump up the calories.”
She also pointed to human error as a major contributor.
“Someone might scoop in 25 fries instead of 20. Or add extra sauce without thinking — and sauces are often very high in fat,” she said. “Small changes like that can add up quickly.”
While some variation is expected, Thornton-Wood believes chains should be doing more to tighten control and ensure that what’s on the menu better reflects what’s on the plate.
Calorie labeling was introduced to guide healthier choices
Across the globe, calorie labeling regulations have been introduced to help people make health-conscious decisions when eating out.
In the U.S., federal law requires chain restaurants with 20 or more locations to display calorie counts on menus. This was part of a broader effort to address growing rates of obesity and diet-related chronic illnesses, such as type 2 diabetes and heart disease.
Similar policies exist in many other countries, aimed at making nutrition data accessible and transparent. However, as this BBC investigation shows, printed numbers may not always reflect the truth — which undermines the purpose of such regulations.
Fast-food companies respond to the findings
After being contacted by the BBC, each of the fast-food brands involved issued a response.
KFC acknowledged that natural variations in ingredients like chicken can lead to calorie differences, but said it is reviewing its processes to determine whether the discrepancies fall outside acceptable ranges.
McDonald’s said the tested burger may have been prepared incorrectly, which would explain the calorie overage. The company stated it had reminded the restaurant of proper preparation protocols.
Greggs also cited natural variation as a cause but emphasized that it is working with suppliers and staff to enhance consistency and accuracy moving forward.
Calorie counts matter — but they’re only part of the picture
While many nutrition professionals agree that calorie labeling is a helpful tool, they also stress that it’s only one part of a much larger equation.
Food quality, nutrient density, portion size, and eating habits all play crucial roles in long-term health. Still, for people trying to lose weight, manage chronic conditions, or simply eat more mindfully, accurate calorie information is a basic necessity.
As Morning Live reporter Briony May Williams concluded, “For calorie labeling to work, the numbers on the menu need to mean something. Right now, that trust isn’t guaranteed.”
What consumers should keep in mind
Given the inconsistencies exposed, consumers may want to approach calorie counts in restaurants with a degree of skepticism. Here are a few practical tips to stay on track:
- Treat listed calories as estimates, not facts
- Request customizations like no sauce or dressing on the side
- Be mindful of portion sizes, especially with sides and condiments
- Focus on overall food quality, not just the number
- Balance restaurant meals with home-cooked options when possible
While these steps can help, the responsibility doesn’t rest on consumers alone. Health experts and public officials agree that restaurant chains must improve their accuracy and transparency to ensure that menu labeling can fulfill its intended public health role.
Until then, navigating fast-food choices may require a bit more caution — and perhaps, a 31% margin of error.
