9 major diet mistakes the 2020 presidential candidates make all the time - and how to avoid them

Klobuchar, who was on an airplane with no forks in sight, reportedly ended up pulling the comb from her purse and using it to down the salad. Afterwards she apparently asked an aide to wash the comb, as the New York Times recently reported.

While the hygiene and management behaviors at play here might be questionable, filling your plate with dark leafy greens and colorful vegetables can be a great way to incorporate fiber and cancer-fighting phytochemicals into your diet. Be careful which salad you choose, though: the Physicians Committee for Responsible Medicine says there are easily 100 chain-restaurant salads that are worse for you than a Big Mac based on metrics like calories, cholesterol, and salt content.

"You know, when you have been working for a long period of time and you're really hungry, you can get kinda primal!" Harris told Noah, laughing as she mimed hunching over and shoveling food into her mouth. "Everybody back the you-know-what off, I'm hungry!"

Waiting hours to eat leaves people ravenous and therefore more likely to reach for calorie-rich convenience foods. To avoid hanger, nutritionists recommend keeping some healthy snacks on hand, like a handful of nuts or some cheese cubes. Staying hydrated helps, too.

Dietitian Jason Ewoldt from the Mayo Clinic recently told Business Insider that a lot of people also misinterpret thirst for hunger.

"A lot of times, people just seem to be a little dehydrated," he said.

Studies suggest that well-watered people not only consume fewer calories than dehydrated folks, they also take in less sugar, fat, salt, and cholesterol on a daily basis.

Studies show that people who cook at home eat less sugar and consume fewer calories than restaurant-goers.

"Last weekend I made swordfish and I toasted cardamom and cumin seeds and did that with garlic and onion and lemon and kind of marinated it, and it was really delicious," Harris told The Cut in August.

Nutritionists agree that a Mediterranean-style diet that's rich in fresh fish and produce is the best eating plan for a long, healthy life.

New York Senator Kirsten Gillibrand recently got skewered for trying to eat fried chicken with a fork. But overall, her diet is nothing to scoff at.

Gillibrand stays hydrated with plenty of water and unsweetened coffee. Breakfast for her might be a bowl of plain oatmeal with some berries on top, as Politico previously reported.

Avoiding added sugar is a smart strategy for staying trim, since we know sweets contribute to weight gain.

But the science doesn't support Gillibrand's tendency to snack on low-fat cheeses and non-fat, sugar-free yogurts. There's really no reason to shun healthy fats — scientists are discovering that the ways protein and calcium are arranged in full-fat cheeses may actually help protect our hearts. Generally speaking, nutritionists are coming around to the idea that sugar — not fat— has been the real culprit for weight gain in the US.

But scientists know that high-glycemic-load foods like doughnuts, which are carbohydrate-heavy but nutrient-poor, are terrible fuel.

Eating donuts and other high-glycemic-load foods (such as white rice, white bread, candy, and soda) on a frequent basis is associated with health problems including heart attacks, strokes, Type 2 diabetes, and cancer.

In 2016, Warren toted boxes full of Dunkin pastries to a sit-in that Democrats were holding to push forward a vote on gun control.

Because items like doughnuts are quickly converted into sugar in the body, they set us up for a quick crash.

"I remember my last non-vegan meal was Election Day, November 2014," Booker recently told VegNews.

But he hasn't always approached the diet in the healthiest way.

"Last year I was too much of a junk food vegan: empty carbs, sugar, fat, etc," he wrote on Facebook in March.

Now, he's changing his ways.

"I find myself more and more rejoicing in the delicious simplicity of a whole food, plant-based diet," he said.

Booker also occasionally opts for a day of fasting and says he is "loving it."

Both intermittent fasting and plant-based diets that feature whole grains, nuts, seeds, and vegetables are gaining steam as science-backed techniques for living a long, healthy life. But you certainly don't have to go vegan to reap any of the benefits.

His family finally hosted an intervention.

"By the time of Iowa’s Democratic caucuses on Feb. 1 [2016], his hotel spread included turkey sandwiches, pineapple, and strawberries" the Washington Post reported.

The Vermont senator enjoys his steak medium-rare.

But regularly fueling up on meats, which have no fiber, can lead to health problems. Gout, an inflammatory arthritis that can lead to severe and sudden foot and hand pain, is making a comeback in the US as more Americans load up on purine-rich foods and drinks — things like bacon, steak, scallops, veal, and alcohol.

Drinking coffee is good for our hearts and can also lower one's risk of developing some cancers, including breast, prostate, and liver.

But Schultz is also known to drink the fruit smoothies on the Starbucks menu. Although a smoothie does pack in more belly-filling fiber than a pressed juice, drinking one for breakfast will cause you to start the day with a blood-sugar spike. It's best to avoid the pulverizing and eat whole fruits instead.

According to former aides, one of Trump's favorite dinners is "two Big Macs, two Fillet-O-Fish, and a chocolate malted" from McDonald's.

"On Trump Force One there were four major food groups: McDonald's, Kentucky Fried Chicken, pizza, and Diet Coke," former Trump campaign aides Corey Lewandowski and David Bossie wrote in "Let Trump Be Trump."

The president has even served Wendy's and McDonald's to guests at the White House.

Eating a lot of processed food like french fries and milkshakes can lead to long-term weight gain. Scientists think part of the reason that people who eat fast food often pack on pounds is that those items don't satisfy our hunger the same way nutritious, fiber-filled whole foods do.

Trump's doctors report the commander-in-chief is in "very good health overall," but he's gained four pounds since last year, which qualifies him as obese. The doctors reported that they've upped his dose of Rosuvastatin, which helps lower cholesterol to reduce a person's risk of stroke or heart attack.

Data from an HSBC global research report released Tuesday shows that Americans are now spending just one hour a day eating. Devoting less time to meals makes it very difficult to nourish ourselves properly.

For example, Rep. Alexandria Ocasio-Cortez (who's not running in the 2020 election) recently told Stephen Colbert she was so exhausted after a long day on the Hill that she huddled under a blanket and downed a pint of Ben and Jerry's Americone Dream instead of eating dinner.

Those types of situations come with a cost: 38% of Americans are obese. By comparison, Italians, who spend over two hours a day eating (and cook more food at home) have a much lower obesity rate of 10%.