You may not recognize John Mackey’s name, but you definitely know his business. Mackey is the founder and CEO of healthy supermarket chain Whole Foods Market, and he has a new book out called The Whole Foods Diet: The Lifesaving Plan for Health and Longetivity . In his book, Mackey details how he became a healthy eater after growing up eating junk food, and the vegan diet he says revolutionized his life.
In a new interview with NBC News about his book, Mackey says he became a vegetarian in his 20s, but started eating fish when he dated a woman who wasn’t a vegetarian. “And gradually, over time, I was starting to gain weight,” he says. “My biometric measurements were not as good as they used to be. I was getting older. I just thought, ‘Oh, this is coming with age.’”
But Mackey says his health began to improve “almost immediately” after he adopted a vegan diet. “I started losing weight and I felt better,” he says. After a year, his health plateaued so he cut out sugary and highly refined foods as well. “When I stopped eating all those processed foods and combined that with a plant-based diet, my health was just amazing,” he says. “I weigh the same as I weighed when I was 18 years old…I’m an extremely healthy person now.”
Mackey points out that he went from being a kid who wouldn’t eat vegetables to teaching himself to “love every single vegetable out there”—and he urges people to try to do the same. “You can teach yourself to enjoy any type of food , so why not teach yourself to love the healthiest foods in the world?” he says. “When you combine the things our body naturally craves—whole starch foods (sweet potatoes, brown rice, beans, etc.) with fruits and vegetables—you can eat all you want and you’ll lose weight.”
Experts say that while people can lose weight on a vegan diet, it’s not a guarantee. (Also, not that gaining weight is inherently a bad thing, but eating all you want—even if it’s healthy—can still affect how much you weigh).
If your goal is to lose weight, the process involves many more aspects than just what you eat and whether you follow a plant-based diet . Sure, exercise is a factor, too, but so many other things come into play. Components like stress and sleep, along with things you can’t fully control, like health conditions and hormonal fluctuations, can play a big role in your weight as well.
It’s true that there is some science behind veganism potentially promoting weight loss, but the reason why is simple.
Many studies have shown that veganism is associated with a lower weight, Fatima Cody Stanford, M.D., M.P.H., M.P.A., instructor of medicine and pediatrics at Harvard Medical School and obesity medicine physician at Massachusetts General Hospital, tells SELF.
For example, a cross-sectional study of more than 70,000 people published in the Journal of the Academy of Nutrition and Dietetics in 2013 found that vegans had the lowest BMI of people with different dietary habits (ranging from non-vegetarian to vegan), even though everyone ate the same amount of daily calories. And a meta-analysis published in the journal Nutrients in 2014 looked at over 100,000 study participants and found that vegan diets are linked to a lower risk of developing obesity (as well as hypertension, type-2 diabetes, and heart disease). Another meta-analysis published in the Journal of General Internal Medicine in 2015 discovered that people on a vegetarian diet—especially those on a vegan diet—saw better weight-loss results than dieters on other eating plans. Of the more than 1,000 people who followed a specific diet for nine to 74 weeks, vegans on average lost about 5.5 more pounds than non-vegetarian dieters (vegetarians lost about three pounds more than those on a diet that included meat).
Sonya Angelone, R.D., a spokeswoman for the Academy of Nutrition and Dietetics, tells SELF that veganism can cause weight loss simply because it’s a form of food restriction. “Anything that restricts food, even temporarily, can promote weight loss in the short term,” she says. Certified dietitian-nutritionist Lisa Moskovitz, R.D., CEO of NY Nutrition Group , agrees. “When most people think of veganism, they think of eating strictly veggies and cutting out high-fat animal foods like cheese, burgers, and bacon,” she says. “Naturally when you eliminate fatty animal foods, you may notice weight loss due to less calorie intake, and of course, animal fat is typically artery-clogging fat, which is not recommended .”
With that said, going vegan doesn’t automatically mean you’re going to be eating healthier or less food than usual.
Although there aren’t as many processed vegan foods as non-vegan ones, they’re still out there. Plenty of foods like chips, non-dairy ice cream, and cookies may fall into the vegan category but still not be healthy , Angelone says. As a result, a person may end up eating a diet that’s technically vegan, but high in sugar, carbohydrates, and calories. The limited category of things vegans can eat can lead to nutrient deficiencies, Angelone says, so vegans need to be careful to get enough calcium, iron, vitamin B12, zinc, and omega-3 fats.
Vegans also may deal with cravings and have to work harder to be satiated, potentially leading to eating more than they used to. “It can be even harder to keep portions and calories in check when eating a strict vegan diet because, by eliminating good quality sources of protein like eggs, fish, dairy, and organic lean meats, it can be harder to stay full and keep cravings in check,” Moskovitz says. That’s why she recommends vegans focus on consuming more protein-rich foods such as beans, lentils, quinoa, soybeans, or tofu, on a daily basis.
Of course, there are many vegans who eat nutritiously with no problems, but being healthy while vegan can actually be pretty hard work. Luckily, you don’t have to go vegan to reap the benefits of a plant-based diet. If you want to go vegan because you truly believe in the lifestyle, have at it. But if you’re considering striking foods you love from your life and going vegan just in an effort to lose weight, it’s absolutely not necessary. If you’d like to eat a healthier diet—whether weight loss is a goal of yours or not—Stanford says it’s important to make sure you’re incorporating lean protein, vegetables , whole grains, and fruits into your diet. “It is also important to realize that the less processed a diet the healthier it is overall,” she says.
It’s also important to remember that undertaking a diet that’s too restrictive for you can lead to dangerous bingeing and yo-yo dieting , which over time can contribute to problems with high blood pressure, high cholesterol, and heart disease.
That’s why it’s key to figure out how to fuel your body and mind in a way that’s safe and realistic for you. “There is no one strategy that is universally effective in helping people to achieve a healthy weight,” Stanford says. And, of course, if you’re struggling to find a diet that works for you, seek out a certified dietitian—he or she can help guide you toward an eating plan that best suits your needs.
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