Food News & Facts
A Wake-Up Call for Evening Eaters
Fueling up just before bedding down may lead to higher body fat.
Much has been written about eating at a later clock hour, yet a recent 30-day study of 110 college-age participants examined an additional factor: onset of the body’s production of melatonin, a hormone involved in the cycles of sleeping and waking. Melatonin is regulated by the body’s internal clock.
In the first study of its kind, published in The American Journal of Clinical Nutrition, nine sleep-medicine researchers looked at when people eat in relation to their circadian clock—and how that affects body composition (2017; doi: 10.3945/ajcn.117.161588). According to lead researcher Andrew McHill, PhD, “The closer you eat to your melatonin onset, the more likely you are to have a higher percent body fat. In our population, it did not matter what a person ate, how much they ate or how much they exercised when it came to predicting their body composition,” he says. All that mattered, explains McHill, was “the timing of calories relative to melatonin onset.” Further, he adds, “other studies have shown that if you restrict the time a person eats to just the daytime hours, it helps to reduce weight. We think our study helps to explain why they find these results.”
Defining lean as “5%–20% body fat for men and 8%–30% body fat for women,” and nonlean as “greater than 21% body fat for men and greater than 31% for women,” McHill et al. discovered that the nonlean group consumed most of their calories 1.1 hours closer to melatonin onset than the lean group. There were no differences between the two groups as to the clock hour of food consumption. Eating time was recorded via a time-stamped picture (via a mobile phone app), plus an in-lab assessment of body composition and timing of melatonin release.
While fitness professionals have various methods for assessing clients’ body composition, McHill notes that “unfortunately, you can only measure the timing of melatonin onset in very controlled conditions—normally in a laboratory setting. However, we typically think melatonin begins to rise about 2 hours prior to habitual bedtime. So, the best advice I can provide is to limit the number of calories you eat during that time, as they may ‘count’ for more than just a calorie.” This is an easy—and evidenced-based—tip to share with clients whose New Year’s resolution is to lose weight or belly fat. Shifting eating time should take little effort to implement, at least in theory, and could pay off in very real, measurable success.
In the Pink With Purple Tea
Want your polyphenols, antioxidants and anthocyanins (found in raspberries, purple grapes and blueberries) in a ready-to-drink form? Kabaki Kenyan Purple TeaTM is now on the market in five flavors: raspberry, peach, lemon, lightly sweetened and unsweetened. Processed in the same way as green tea, purple tea is lower in caffeine than its green cousin and has twice the antioxidant activity. What’s more, purple tea, made from Kenyan purple tea leaves, has shown promising positive effects on body weight, body mass index and body fat mass in small-scale clinical human trials. Values-based consumers will be happy to know that founder Martin Kabaki has committed 10% of the profits to a Kenyan medical clinic.
When junk food costs more, kids may buy less.
Time to Raise Some Snack Prices?
If you work at a facility that caters to youth, you may want to suggest raising the prices of energy-dense, nutrient-poor (EDNP) snack foods offered on-site—and replacing them with nutritious alternatives. A study published this past October in the journal Appetite investigated snack choices among 116 children aged 8–11. Results showed that children who received an allowance (which suggests experience with cash was important) could be successfully motivated to choose healthier snack options when EDNP foods were priced high (2017; 117 ).
While the type of food (for example, cookies) was still the most important factor for the kids, price mattered, too, whether they were spending their own money or not.
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In findings published in August in Cell Chemical Biology, researchers from Aarhus University in Denmark revealed that the human body uses its own fat metabolism process to protect against the negative effects of sugar (2017; 24 , 935–43.e7). This may explain the link between low-carb diets and a reduced risk of diabetes, Alzheimer’s, cancer and other age-related diseases, according to a September article in nutraingredients-usa.com (Cash 2017).
Specifically, what the researchers discovered was that fat metabolism takes place simultaneously with the detoxification of blood sugar’s harmful substances (for example, methylglyoxal)—knowledge that could lead to better techniques for preventing some diseases. Methylglyoxal is toxic to cells and is especially problematic for people with diabetes. In this study, the researchers noted that ketone acetoacetate—a natural product of the liver’s breakdown of fatty acids—inhibited methylglyoxal, and that the interaction between the two metabolites caused the emergence of a third metabolite called 3-HHD (3-hydroxyhexane-2, 5-dione), which does not have the harmful effects of methylglyoxal. See “The Ups and Downs of Ketogenic Diets” below for a sports dietitian’s take on how ketosis can work for athletes (or not).
The Ups and Downs of Ketogenic Diets
The metabolic state in which the body breaks down fat for energy is called ketosis. This happens when there’s not enough carbohydrate readily available to use as fuel. A ketogenic diet, which is high in fat and low in carbohydrate (to encourage ketosis), has gained popularity over the past few years. Originally used to treat those suffering from epilepsy, this diet is currently being researched for its effect on other neurological diseases, as well as diabetes, certain cancers, polycystic ovary syndrome and heart disease. Many people are also turning to the ketogenic diet for improved athletic performance and weight loss, says sports dietitian Emily Bailey, RD, CSSD, LD, NASM-CPT, at Leaves of Life Integrative Wellness Center in Columbus, Ohio. She offers this snapshot of the emerging trend:
“The ketogenic diet typically recommends consuming about 70% of calories from fat, 10%–20% from protein and 5%–10% from carbohydrates,” says Bailey. On the downside: “This is a major adjustment for many people who have traditionally consumed the Standard American Diet, and [the switch] can result in low energy, constipation or moodiness as the body adjusts.” A “major plus” of the ketogenic diet, she adds, is that it promotes the elimination of processed foods and the addition of more green vegetables.
Bailey emphasizes the importance of using research responsibly when discussing this or any diet with clients, and she suggests referring them to an appropriate professional before they make a major dietary change, especially if they have existing health conditions.
The Power of Making Nutrition Personal
The Mayo Clinic and the Archer Daniels Midland Company (ADM) just may be trendsetters, as they’ve teamed up to explore personalized nutrition, focusing on the ways that “complex interaction at the microbial level may impact a variety of health conditions,” according to Vikram Luthar, president of ADM’s Bioactives unit.
Personalized nutrition is essentially looking at genetic differences and their influence on metabolic responses. By creating individualized dietary advice (as opposed to general advice, such as, “Eat more fruits and veggies”), nutrition experts can help clients prevent, ameliorate or even cure some diseases.
This particular collaboration is with Mayo’s Microbiome Program and will investigate the relationship between body fat reduction and specific pro- and prebiotics, as well as other nutrients (mayoresearch.mayo.edu/center-for-individualized-medicine/microbiome-program.asp). According to Luthar, once that initial goal is met, the two powerhouses want to develop ingredients that will have “beneficial impacts on conditions ranging from skin health to gluten intolerance.”
The Mayo Clinic will provide data analysis, modeling and gut microbiome expertise, while ADM will contribute its experience in food ingredients, commercialization abilities, strain development and genomics.
If they aren’t already fielding questions on personalized nutrition, fitness pros¬—especially those with nutrition expertise—are soon going to be asked for their opinions and advice, especially with the Mayo Clinic in the mix. It could be that “Go with your gut” is the perfect personalized nutrition advice.
Not All Plant-Based Diets Are Equal
With so much research emphasizing the benefits of a plant-based diet (see our own piece in the Fall 2017 Nutrition column), clients may begin to think that all plant-based diets are superior to other ways of eating. This, however, is not the case. In a groundbreaking study published last summer in the Journal of the American College of Cardiology, Satija et al. examined the “associations between plant-based diet indices and [coronary heart disease]” (2017; 70 ) and discovered that plant-based diets that are high in less-healthy plant foods may not offer the health perks some people expect.
Over 200,000 women and men were included in longitudinal studies that analyzed eating habits. Plant foods received positive scores, and animal foods got negative scores. Additionally, the researchers developed two diet indexes: a healthful plant-based diet index (hPDI), where foods like whole grains, vegetables, fruits, legumes/nuts, oils and coffee/tea received positive scores; and an “unhealthful” index (uPDI), where less-healthy plant foods (like sweetened beverages/juices, refined grains, sweets and potatoes/fries) scored higher. Over 4,800 person-years later, uPDI was positively associated with coronary heart disease (CHD), while hPDI was inversely associated with CHD. Bluntly put, a diet of “unhealthful” plant-based foods was about as likely to contribute to CHD as one centered on animal-derived foods.
Kim Allan Williams, MD, and Hena Patel, MD, wrote an accompanying editorial to the published research in which they mentioned a 29% lower risk of CHD for vegetarians as compared with omnivores. Based on this research, they added that it’s increasingly important for specialists, including fitness and nutrition professionals, to recommend the right kind of plant-based products to clients. While this may seem obvious to most fitness pros, the lead study author, Ambika Satija, ScD, noted that previous studies had tended to lump together all plant-based diets as “vegetarian,” without distinguishing among the types of plant-based foods consumed. What to tell clients? Put down the fries and pick up the cauliflower.
Recipe: Dairy-Free Dungeness Crab and Sweet Potato Bisque
When Lindsay Mauch, founder of LTM Digital and owner of FitAndAwesome.com, received two fresh cooked Dungeness crabs as a gift, it was the first time she had ever tried them. She decided to craft a healthy soup recipe. Not wanting to use heavy cream, she made the recipe dairy-free and paleo friendly by using coconut milk and chicken-bone broth. This recipe serves 10–12 people, so it’s perfect for a night of entertaining, says Mauch. If you want a smaller batch, the recipe can be cut in half.
2 t coconut oil
1 large yellow onion, chopped
4 cloves garlic, chopped
4 sweet potatoes, cut into chunks
1 lb chopped carrots
2 cans full-fat coconut milk
8 C chicken-bone broth
1 lb cooked Dungeness crab meat
salt and pepper, to taste
chives, for garnish (optional)
Heat the coconut oil in a large heavy-bottomed pot over medium heat. Add the onion, garlic, sweet potatoes and carrots, and sauté until golden brown, about 10 minutes. Add the coconut milk and chicken-bone broth. Bring to a boil. Cover and simmer for 20–30 minutes, or long enough to ensure the sweet potatoes and carrots are soft. Remove from heat.
To blend the soup, either pour all of the contents of the pot into a blender or use an immersion blender straight in the pot. Once the soup is smooth, add the crab meat and heat through. Serve in bowls and garnish with fresh chives.
Nutrition information (per serving): 224 calories, 11 g protein, 17 g carbohydrates, 5 g sugars, 16 g fat, 178 mg sodium.
An Avocado a Day...
Do you work with older adults? If so, you may want to recommend they up their guacamole consumption. A recent study out of Tufts University (funded, but not influenced, by the USDA and the Hass Avocado Board) looked at ways that practical dietary choices could be part of healthy aging. To that end, researchers designed a protocol to examine the role that avocado intake might play in brain health, with results reported in the September issue of Nutrients (2017; 9 ). Avocados contain lutein, an antioxidant whose levels in the brain and macula (part of the eye) are related to cognitive health.
Over a 6-month period, 48 healthy men and women participated, with some of them randomly assigned to eat one avocado daily. Lutein levels in the macula and blood were assessed at 0 (zero), 3 and 6 months, as was brain function. At the 6-month mark, the avocado eaters had boosted their lutein levels and showed improvements in memory, attention span and problem-solving efficiency. This has significant implications for the aging population.