51视频

09/02/2021
By Katharine Webster

A sustainable diet is healthier for the planet 鈥� and for us, says Biomedical and Nutritional Sciences Assoc. Prof. Kelsey Mangano.

There are three keys to helping the environment while improving our own health, she says: Eat a wide variety of foods, cut portion sizes and food waste, and substitute plant proteins for some animal proteins.

College is the perfect place to do it, since the dining halls offer a range of choices, from fruit and salad bars to vegetarian and vegan entrees, she says.

鈥淰ariety in our choices is going to be the most beneficial, and listening to our hunger cues,鈥� she says. 鈥淭ry swapping out meat, dairy and eggs for plant alternatives 鈥� and try new things. It鈥檚 OK if you don鈥檛 like them the first time. Eventually, you鈥檙e going to find the plant choices that you do like.鈥�

Mangano, a member of the university鈥檚 Center for Population Health, researches the nutritional value and health effects of different protein sources, as well as gut health and food additives. In addition to advanced nutrition courses, she teaches a popular course, Nutrition and Wellness, that counts as a science requirement for non-science majors.

Recently, she sat down to talk with us about the connections between food and a healthy planet.

Q: What is a sustainable diet?

A: It鈥檚 part of a food system that provides healthy food to all people in a way that protects the environment.

There are so many food inequities in the United States and around the world. Making sure that all people have access to healthy, nutrient-dense foods is the foundation of a sustainable food system. That means a shift away from overconsumption of all foods and toward a more varied diet that includes more plants and fewer animal products.

Q: The recently released a report with a bleak warning about the environment, saying it鈥檚 鈥渃ode red for humanity.鈥� What were your main food-related takeaways from the report?

A: Of the 4 billion tons of food produced globally each year, one-third of it is wasted. That blew my mind, especially since there are such high rates of food insecurity.

In the United States, we have an obesity epidemic that is getting worse every year. Overeating is bad for our health, and through that overconsumption, we鈥檙e using all these fossil fuels in agribusiness to produce highly processed foods that we shouldn鈥檛 be eating in the first place.

The No. 1 thing we can do for ourselves and the planet is to reduce food waste overall. It鈥檚 really about getting back in tune with what our bodies need, and those hunger cues.

In the dining hall, try putting a smaller amount of food on your plate. Eat it, and then consider, 鈥淎m I still hungry?鈥� And if you鈥檙e still hungry, you can always go back for more.

Q: The says cows and rice are the two biggest agricultural sources of methane gas, one of the most damaging greenhouse gases. Is pork or chicken better for the environment than beef? What about eggs and dairy products?

A: All ruminant animals 鈥� cows, sheep and goats 鈥� release methane gas during digestion, so eating dairy products is only slightly better for the environment than eating beef, lamb and goat.

Rice production releases more methane gas than wheat or corn farming because of certain bacteria that grow in rice paddies when they鈥檙e flooded. But overall, industrial animal farming uses far more fossil fuels and other resources than plant agriculture, so eating plant-based foods is more sustainable than consuming beef, pork, chicken, fish, dairy and eggs.

However, animal products provide a special combination of nutrients important to our overall health, so eating moderate amounts of sustainably produced meat, eggs and dairy from local farms is good for us. Pay attention to where your food comes from.

Q: If someone says, 鈥淚 hate tofu and I鈥檓 never going to give up steak,鈥� is there anything else they can do to cut down on greenhouse gas emissions?

A: I ask my students to self-evaluate their food intake for a week. If someone finds that they鈥檙e eating meat at every meal 鈥� a sausage, egg and cheese sandwich for breakfast, a deli meat sandwich for lunch and then a big piece of meat for dinner 鈥� they can try to remove meat from one or two meals a day and replace it with plant protein.

Soy is the only plant we know of that鈥檚 a complete protein comparable to meat, so tofu and tempeh are good protein sources. Other beans and legumes combined with whole grains, nuts and nut butters, some veggie burgers and even mushrooms are good choices, too.

Plant proteins provide so many vitamins and minerals, antioxidants, fiber and healthy oils that aren鈥檛 typically in animal protein. By swapping out animal protein for plant protein once or twice a day, you鈥檙e really bumping up the nutritive value of your diet and you have less of a carbon footprint. It鈥檚 a win-win.

Q: What about athletes, who may have different protein needs than the general population?

A: We now have research showing that younger adults only need 20 grams of protein in one meal or snack to stimulate new muscle growth and bone tissue. That鈥檚 about 3 ounces of meat, fish or poultry, or a veggie burger with a slice of cheese (or vegan cheese) at each meal. This is a good starting point, and then, depending on the athlete鈥檚 size and activity level, they can increase the protein in their meals as needed. If you over-consume protein, you will just turn it into fat tissue.

Q: What about some of the new meat substitutes, like Impossible Burgers and Beyond Burgers?

A: Say somebody has a portion-controlled, 4-ounce steak and a plate full of fruits and vegetables: I鈥檇 much rather see that than something that鈥檚 highly processed and loaded with salt or synthetic food additives.

Many meat substitutes currently on the market are highly processed. Research in my lab and across the country suggests that processed foods and some food additives increase inflammation in the gut, which leads to chronic disease development, such as diabetes and cardiovascular disease.

I鈥檓 an omnivore: I eat a mixture of plant protein and sustainably raised meat, but I try to eat food that鈥檚 as minimally processed as possible.

Q: What are some other tips for healthy, sustainable eating?

A: Take advantage of the unique, diverse environment in Lowell. If you can afford to eat out, it鈥檚 a neat opportunity to expand your cultural awareness and try more plant-based foods. Although plant proteins are not traditionally a staple in the westernized diet, they are a staple throughout the rest of the world.

There鈥檚 a big push in university dining for more vegetarian options and more locally sourced food. If you鈥檙e cooking for yourself, Lowell has a every Sunday and an on Fridays from July through October.

Buying locally grown fruits and veggies cuts down on fossil fuels used to transport food long distances, and you鈥檙e also getting more nutrients for your buck because exposure to air, heat and sunlight breaks down important vitamins. For example, you鈥檙e getting 80% more Vitamin C out of the greens in your backyard or from the farm down the street than if you bought them in the grocery store.

Finally, remember that sustainable food systems are those that provide nutritious food for all people. Support Our Students (SOS) is a nonprofit started by UML students that allows you to donate a meal from your meal plan to someone in need.