Everyone wants to know: What's in a hotdog? But the more relevant question should be: How many minutes of my life is a hotdog worth? Now we know, thanks to a new study on the health and climate costs of the foods we eat.

When we choose unhealthy foods over a diet of mostly whole plant-based foods like fruit, vegetables, nuts, and grains, how much of our longevity are we giving up? Until now, we didn’t have the answer, but scientists have devised a system to determine precisely the health and climate impact of the foods we choose to eat. Researchers put firm numbers to our dietary choices in a fascinating new study, quantifying the risks and benefits to our health and the environment.

They found that compared to ‘win-win’ foods such as nuts – which can actually add 25 minutes of healthy living to your lifespan – processed meats such as hotdogs steal 36 minutes of our healthy lifespan, as well as create irreversible damage to the environment. The impact on our lives and the planet is equally alarming for other meats and dairy products.

The cost of eating meat, full-fat dairy, and processed food is now measurable

In essence, the new research suggests that animal products rob people of the opportunity to grow older in good health and with the highest quality of life. In contrast, eating a plant-based diet can support our health and longevity, allowing us to maintain an active and healthy lifestyle as we enjoy a longer lifespan. Add to that the relative environmental benefits of a plant-based diet, and there is no question of which way we should be eating.

Switching 10% of calories from beef to plant foods adds 48 minutes to your life

Motivated to identify environmentally sustainable foods that promote health, scientists at the University of Michigan developed the Health Nutritional Index to classify over 5,800 foods, ranking them in terms of healthy minutes that can add to –or steal from – your life. These "healthy minutes" are defined as disease-free, good quality lifespan. The researchers also assessed the environmental impact of the foods then crunched the numbers to classify them in a traffic light system.

The study published in the journal Nature Food found that substituting just 10 percent of daily calories from beef and processed foods for fruits, vegetables, nuts, and legumes gains you 48 healthy minutes of healthy lifespan and reduces your dietary carbon footprint by a third. This is an enormous improvement for such a small dietary change, benefitting not only the individual but the planet too.

The good, the bad, and the ugly, or the "green, amber and red" light foods

The researchers identified negative scores for red meat, breakfast sandwiches, burgers, and frankfurters, indicating that eating a serving of these foods damages our health and planet. Conversely, legumes, whole grains, fruits, and non-starchy vegetables had positive scores for the environment and add minutes to our life.

The study authors classified foods into a three-color traffic light system based on their nutritional and environmental impacts:

  • The green zone represents foods to increase because they are nutritionally beneficial and have a low environmental impact. The authors note that these foods are a ‘win-win solution.’ Beneficial foods include nuts, fruits, field-grown vegetables, legumes, whole grains, and some low-environmental impact seafood.
  • The amber zone represents foods that are either slightly nutritionally detrimental or generate moderate environmental impacts. These foods include poultry, dairy products, egg-based foods, cooked grains, and vegetables produced in a greenhouse.
  • The red zone represents foods that people should avoid or reduce. These foods have considerable negative impacts on health and the environment and include processed meat, beef, pork, lamb, cheese-based foods, shrimp, and some salmon.

Small changes have powerful benefits

The new study adds weight to current dietary guidelines and can inspire people to make beneficial small changes.

“Generally, dietary recommendations lack specific and actionable direction to motivate people to change their behavior, and rarely do dietary recommendations address environmental impacts,” said Katerina Stylianou, who did the research as a doctoral candidate and postdoctoral fellow in the Department of Environmental Health Sciences at U-M’s School of Public Health in a press release.

“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” added senior author Olivier Jolliet.

Start by eliminating beef, processed meat, and sodium

The authors gave their perspective in an interview,  identifying priorities for people to act urgently on.

‘’When it comes to environmental sustainability, we found striking variations both within and between animal-based and plant-based foods. For the “red” foods, beef has the largest carbon footprint across its entire life cycle – twice as high as pork or lamb and four times that of poultry and dairy. From a health standpoint, eliminating processed meat and reducing overall sodium consumption provides the largest gain in healthy life compared with all other food types’’.

They added ‘’therefore, people might consider eating less of foods that are high in processed meat and beef, followed by pork and lamb’’.

Additionally, they noted that the ‘green’ choices have a lot of flexibility and appeal to all income levels, tastes, and cultures. However, greenhouse-grown vegetables scored poorly on environmental impacts due to the combustion emissions from heating.

Eat plant-based seafood alternatives

Shrimp and salmon were included in the red zone, and the authors recommend that if someone eats fish and seafood, they choose types with low environmental impact.

Following the popular Netflix documentary Seaspiracy, many people have decided to avoid fish and seafood for environmental and ethical reasons. However, there is now an extensive range of plant-based seafood and fish alternatives available for people to choose from.

The nutritional profile of plant-based seafood varies according to product and brand. People should look for lower fat and sugar and higher protein products with as few added synthetic ingredients as possible.

A healthy perspective

Still, the scientists are aware of limitations in the study and the need for further research that differentiates individual foods within the same groups, for example, an apple compared to a watermelon.

Furthermore, they advise that people should consider the individual foods in the study within the context of their overall diet, and be aware that overconsumption of some foods is not beneficial ‘’one cannot live forever by just increasing fruit consumption’’ they commented.

Bottom Line: Small dietary changes have huge impacts on health and the planet.

To be healthy and active into old age, start now by swapping out beef and processed meat for plant foods such as legumes, whole grains, and vegetables.

We can all live a longer, healthy life by taking control of what we eat and a plant-based diet serves not only the individual but the entire population on earth.


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