Every hotdog a person eats shortens their life by 36 minutes, according to a new study.
However, a person can also add minutes to their healthy life expectancy by eating better foods. A portion of nuts, for example, adds almost 26 minutes, while a peanut butter and jam sandwich gives a person more than half an hour extra life.
The findings come from experts at the University of Michigan who created a standardised way of assessing the carbon footprint and nutritional impact of almost 6,000 foods.
Their Health Nutritional Index was centred around finding a way to calculate the direct influence of various meals, snacks and drinks. It works by calculating the health burden of one gram of any food, and then scaling this up to a standard serving size.
“For example, we found that, on average, 0.45 minutes are lost per gram of any processed meat that a person eats in the US,” the study authors wrote.
“The 61 grams of processed meat in a hotdog sandwich results in 27 minutes of healthy life lost due to this amount of processed meat alone.
“Then, when considering the other risk factors, like the sodium and trans fatty acids inside the hotdog – counterbalanced by the benefit of its polyunsaturated fat and fibers – we arrived at the final value of 36 minutes of healthy life lost per hotdog.”
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But each item of food contributes to a unique equation and a person does not need to make wholesale dietary changes to reap the rewards, researchers said.
For example, if a meat-eater decides to replace 10 per cent of their daily calories – 250 for men and 200 for women – with nuts, fruits and vegetables instead of processed meat or beef, they will gain 48 minutes of healthy life every day they stick to this change.
This simple adjustment, the researchers said, also has clear environmental benefits and slashes a person’s daily dietary carbon footprint by a third.
The study, published in the journal Nature Food, is based around healthy life expectancy, which is the length of time a person has a good quality of life and is disease free.
“The urgency of dietary changes to improve human health and the environment is clear,” said Prof Olivier Jolliet, study author from the University of Michigan.
“Our findings demonstrate that small targeted substitutions offer a feasible and powerful strategy to achieve significant health and environmental benefits without requiring dramatic dietary shifts.”
The Health Nutritional Index takes into account all aspects of a product’s life cycle, including how it is produced, harvested, processed, consumed and disposed of, as well as how calorific and nutritionally beneficial or detrimental a food was.
Researchers gave each food a traffic light rating based on the results of their analysis which indicated whether people should eat more, less, or about the same.
Salmon scored well for nutritional impact, achieving a green label and adding 16 minutes to a person’s healthy life. However, it got a red for environmental impact, and therefore a red overall, with people encouraged to decrease their consumption of the oily fish.
Chilli con carne with beans is another example of a food being bad for the environment, but good for health.
Cola, on the other hand, got a red for nutrition – thieving 12.5 minutes of life per drink – but a green for environmental impact, but this still led to a recommendation to decrease how much a person consumes.
Foods are only recommended if they scored a green for both nutrition and environment. All of the green dishes are meat-free, with plenty of fish, bean and nut-based items.
“Previous studies have often reduced their findings to a plant versus animal-based foods discussion,” said Katerina Stylianou, the lead author of the study.
“Although we find that plant-based foods generally perform better, there are considerable variations within both plant-based and animal-based foods.”