少吃垃圾食物 研究：驚人的溫室氣體排放，來自不營養的飲食

Cutting out that sugary morning pastry and those fries for lunch might help fight the climate crisis, new research from the University of Leeds has concluded.

Many less nutritious foods and drinks account for nearly a quarter of diet-related greenhouse gas emissions, the research team found, after studying more than 3,000 generic foods and 40,000 branded items.

Meat explained 32 percent of diet-related greenhouse gas emissions; 15 percent from drinks; 14 percent from dairy; and eight percent from cakes, biscuits and confectionery.

Non-vegetarian diets had greenhouse gas emissions 59 percent higher than vegetarian diets. The diest of men had 41 percent higher greenhouse gas emissions than those of women.

Individuals meeting the World Health Organization’s Recommended Nutrient Intakes, RNIs, for saturated fats, carbohydrates and sodium had lower greenhouse gas emissions emissions compared to those exceeding the RNIs.

The study confirms that diets unhealthy for humans also tend to be bad for the planet. Sweets, cakes and biscuits account for 8.5 percent of food-related greenhouse gases. Drinks such as tea, coffee and alcohol contribute 15.1 percent – for a combined total of 23.6 percent.

While the occasional feast of junk food won’t hurt much, eating less nutritious foods regularly has been shown to lead to increased risks of obesity and chronic diseases. Cardiovascular disease, type 2 diabetes, non-alcoholic fatty liver disease and some cancers all have their roots in excessive junk food consumption.

The work of the Leeds-led team, published in the scientific journal “PLOS ONE,” under the title, “Variations in greenhouse gas emissions of individual diets: Associations between the greenhouse gas emissions and nutrient intake in the United Kingdom,” provides a far more detailed picture of the impact of a person’s diet – and the changes each of us can make in our eating habits to combat climate change, while improving our nutrient intake.

Lead author Dr. Holly Rippin, a post-doctoral researcher at University of Leeds School of Medicine, said, “We all want to do our bit to help save the planet and the decisions we make can contribute to that cause. It’s true that we do need big cultural changes – such as significantly reducing our consumption of meat and dairy products which together contribute around 46 percent of our diet-related emissions.”

“However, our work shows that small changes can also produce big gains. You can live a more environmentally sustainable life by just cutting out sweets and drinking less coffee,” Dr. Rippin said.

The team concludes that a healthy diet based on unprocessed, largely plant-based foods is also a sustainable one. They point to the 2019 IPCC Climate Change report that suggests a switch to this type of diet could prevent one-fifth of premature adult deaths while reducing diet-related greenhouse gas emissions by 80 percent1.

Men’s eating and drinking habits also play a major role, contributing 41 percent more greenhouse gases than the food and drink intake of women – largely due to their liking for meat and, to a lesser extent, for drinks.

Co-author Dr. Darren Greenwood of the University’s School of Medicine said, “Other studies have suggested that men’s higher diet-related emissions reflected their need for more energy. Unfortunately, it appears that they look to get those calories from meat rather than lower impact foods.”

The researchers studied the greenhouse gas emissions linked to production and transport of individual foods and brands and used the World Health Organization Recommended Nutrient Intake guidelines to measure the nutrients of those foods.

They then analyzed the food and drink consumption of 212 adults recorded online using the nutritional analysis software at myfood24 over three 24 hour periods.