Nutrition: The Science of Nourishment

Peak Garden Season, Peak Performance. Local produce is all the rage in summer, and with good reason. Upping your intake offers plenty of perks for a healthier body, wallet and planet.

by Matthew Kadey, MS, RD


Take your taste buds to the Mediterranean: This style of eating, which emphasizes plant-based whole foods, can protect your heart.

There is a lot to adore about summertime, but what foodies rejoice about most is the bounty of fresh fruits and vegetables available from local gardens and markets. These edible plants bring lively flavors and a nutrient payload to summer meals. In fact, summer offers the perfect opportunity to consider leaving those meatarian days behind and embrace a diet focused more on plant-based foods like beans, dark greens and ultrasweet seasonal berries, and less on animal-based foods such as red meat, poultry and cheese. Even the government has given the thumbs-up to the plant-based trend. The Dietary Guidelines Advisory Committee (DPHP 2015) has stated “a diet higher in plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower in calories and animal-based foods is more health promoting and is associated with less environmental impact than is the current U.S diet.”

Now, we’re not saying you have to go “cold Tofurky” and say sayonara to meat altogether. But here are a few of the numerous perks to enjoying all the delicious summer plant foods you can stomach.

A Longer Life
Piling your plate high with fruits and vegetables can help you enjoy more birthday celebrations (Gallagher 2017). “Plant-based diets based on eating mostly whole foods tend to supply higher amounts of fiber, vitamins, minerals, healthy fats and phytochemicals, all of which play a role in disease prevention,” says Sharon Palmer, RDN, author of Plant-Powered for Life. Indeed, a massive review of 95 different studies involving 2 million people published in the International Journal of Epidemiology found that eating just 200 grams of fruits and vegetables daily is associated with a 16% reduced risk of heart disease, an 18% lower risk of stroke, a 4% drop in the chances of developing cancer and a 15% reduced risk of premature death (Aune 2017). A daily tally of just 2 cups spinach, 1⁄2 cup blueberries, 1 small carrot and a sun-kissed peach is enough for you to nail this quota. The researchers found an even greater disease-thwarting benefit by eating 800 g of fruits and veggies each day. Further, there is a raft of research showing that adhering to the Mediterranean style of eating, which emphasizes plant-based whole foods, can go a long way in slashing heart disease risk (Tektonidis et al. 2015; Widmer et al. 2015; Abellán Alemán et al. 2016). And a separate 2017 investigation determined that a flexitarian diet—one that prioritizes planet-based foods, with meats playing a smaller role—can slash the risk for high blood pressure, diabetes and other health woes (Derbyshire 2017).

A Leaner Physique
Some research suggests that swapping T-bone for tofu more often appears to be an effective method for helping people stay on good terms with the scale. Case in point: A 2016 review of studies conducted by investigators at Harvard found that people who are assigned to vegetarian diet groups often lose significantly more weight than those assigned to nonvegetarian diet groups (Huang et al. 2016). “A plant-strong diet can be lower in calories while also richer in wholesome, natural foods that deliver more nutrients and hunger-fighting fiber to aid in weight loss,” says sports dietitian and Ironman® competitor Marni Sumbal, MS, RD, CSSD. Another theory is that a plant-heavy diet that includes higher amounts of indigestible carbs—including resistant starch—can alter the microbiome landscape in the gut in a way that promotes fat loss.

To reap even greater waistline-trimming results, you should eat those summer-fresh fruits and vegetables while they’re raw. Research published in the Proceedings of the National Academy of Sciences postulates that cooking food increases the amount of calories our bodies absorb from it by performing some of the digestive process for us (Carmody, Weintraub & Wrangham 2011). So by crunching your way through uncooked heirloom carrots, you’ll give your digestive tract more of a calorie-burning workout. Raw fruits and vegetables can also have higher amounts of resistant starch, a type of carb the body does not absorb for calories.

A Healthier Wallet
Eating more beans and vegetables can plant more money in your pocket. According to findings of a 2012 Journal of Hunger and Environmental Nutrition study (Flynn & Schiff), a plant-based, extra-virgin olive oil diet can cost about $750 less per year than a more meat-and-dairy-heavy diet based on the United States Department of Agriculture MyPlate. Meat is often the most expensive item in a grocery cart, and high intakes can crowd out vegetables and other nutrient-dense, less-expensive plant foods. The biggest savings comes from growing some of your own grub or buying foods from local sources (see “Why Eat Local?”) when their array of offerings are most abundant.

As a bonus, buying locally grown produce can also boost your community’s economy. One report to the Maine Legislature suggested that shifting just 1% of the state’s household food expenditures to direct-from-farm purchases could increase income of Maine farmers by as much as 5% (Gandee 2002).

A Happier Planet
For the sake of Mother Nature, it’s wise to replace some of the industrial meat on your plate with plant foods. “That’s because animal agriculture is very resource-intensive, including the use of large amounts of fossil fuels, land and water,” says Palmer. Experts from the United Nations Food and Agriculture Organization say that raising cattle for burgers and steaks is generating more global-warming greenhouse gases—including methane-emitting flatulence and the energy needed to grow the grains for feed—than often-vilified transportation (U.N. 2006). And a 2014 study published in The American Journal of Clinical Nutrition showed that vegetarian diets result in almost one-third less greenhouse gas emissions compared to nonvegetarian diets (Soret et al. 2014).

Not ready to ditch meat and dairy entirely? Even eating a semivegetarian diet was associated with environmental perks. In fact, Environmental Working Group says if each American skipped eating meat and cheese just 1 day a week for a year, it would be tantamount to pulling 7.6 million cars off the road. Suddenly, Meatless Mondays seem more appetizing.

Ease Into a Higher Intake
Upping your intake of plant foods and the fiber they contain can come with some gassy side-effects. If you’re not accustomed to a high-fiber diet, be sure that when you add items like beans and lentils, you start with small amounts at a time. The body will eventually adjust.

Why Eat Local?
Of course, you should be saturating your diet with plant foods all year long, but during flip-flop season, they may work harder for you, particularly if you load up on ones grown nearby. “Locally grown fruits, vegetables and legumes are often harvested within a day or two of being sold, and also picked at peak ripeness, which means more nutrition and better flavor,” explains Sharon Palmer, RDN, author of Plant-Powered for Life. In contrast, fruits and vegetables that are transported great distances from farm to store are often picked while unripe, after which they may sit around for several days before being consumed. Both practices, Palmer says, can drain some of their nutrient and antioxidant power.  And while eating more plants and less meat is good for the planet, sourcing that produce locally is even better. A University of Washington study looked at the greenhouse gas emissions related to two meals of apples, asparagus, potatoes and salmon, with the only difference being that one was made with in-state products while the other was made with foods sourced out of state or internationally (Morgan et al. 2008). The findings: Total greenhouse gas emissions for the local meal was about 33% less than the emissions from the feast that required a passport. So, locally sourced plants put you one step closer to a low-carbon diet. Buying locally can also help your community, especially farmers, and that may ultimately benefit you, too. Over time, if enough people limit their “food miles,” farmers will likely increase the variety of edibles they offer locally, growing more exciting, unconventional produce that is brimming with nutritional goodness. Purple kale and ground cherries, anyone?

Protein Power Plants
It’s not just gym talk, it’s true: Active people do need more protein than couch potatoes. Modern research says that number is 1.2 to 1.4 grams per kilogram of body weight for endurance athletes and about 1.7 g/kg for people focused on resistance training. And yes, with some strategic planning, it’s possible to build bigger and stronger muscles on plant protein. “A well-balanced plant-based diet can easily meet the carbohydrate, protein, fat and micronutrient needs of athletes,” says sports dietitian and Ironman competitor Marni Sumbal, MS, RD, CSSD. “Taking pride in meal prep and cooking allows for more nutrient dense options including seasonal vegetables to be included in a plant-heavy diet geared towards performance,” she adds.

Enjoying all the foods below on a given day will provide a 150-pound person with enough plant protein needed to support strength training.

Spinach 2 cups 2 g protein
Peanut Butter 1 tablespoon 4 g protein
Peas 1 cup 5 g protein
Soymilk 1 cup 7 g protein
Cooked Quinoa 1 cup 8 g protein
Almonds 1 ounce 8 g protein
Pumpkin Seeds 1 ounce 9 g protein
Black Beans 1 cup 15 g protein
Tempeh 4 ounce 20 g protein
Plant Protein Powder 1 serving 20 g protein


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Meet our experts

AFM_Author_Kadey Matthew Kadey, MS, RD, is a James Beard Award-winning journalist, Canada-based dietitian, freelance nutrition writer and recipe developer. He has written for dozens of magazines including IDEA Fitness Journal, Runner’s World, Men’s Health, Shape, Vegetarian Times and Fitness.

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