How Good Are Activity Trackers at Counting Calories Burned?

by Dr Alex Jimenez | Diets, Fitness

People who wear activity trackers to count the calories they’re burning are probably not getting accurate estimates, suggests a new study.

Researchers who tested seven popular activity trackers found that while heart rate measurements were generally accurate, none of the devices provided a reliable calorie count.

“At this point with this level of error, I would be wary of using that estimate to alter a calorie-controlled diet,” said senior author Dr. Euan Ashley, of Stanford University in California.

Patients “have been bringing data from these devices to us and some of us were using these devices ourselves,” Ashley told Reuters Health.

Because so little is known about the data’s accuracy, “We realized that we had to do our own study,” he said.

Ashley’s team recruited 60 healthy adults to test seven popular wrist-worn activity trackers: the Apple Watch, Basis Peak, Fitbit Surge, Microsoft Band, MIO Alpha 2, PulseOn and Samsung Gear S2.

Participants wore up to four devices at a time, and they also wore laboratory devices to measure heart rate and calories burned while sitting, walking, running and cycling.

All of the devices but one had an average heart rate error rate below 5 percent. The exception was the Samsung Gear S2, which had an error rate of 5.1 percent.

But for calculating energy expenditure – or calories burned – all of the devices had error rates above 25 percent. The Fitbit Surge had the lowest average error rate for calories burned at about 27 percent. The PulseOn had the highest at about 93 percent, according to a report in the Journal of Personalized Medicine.

Overall, the Apple Watch had the lowest error rates while the Samsung Gear S2 had the highest.

The researchers were surprised at the unreliability of the calorie counts.

The devices “were literally all over the map with error rates,” Ashley said.

Data tended to be less accurate for men, people with higher body weights and darker skin tones, and while walking.

Ashley’s team hopes the devices’ calorie counting technology will improve. “I think we’re all hopeful that as we move forward they will get better,” he said.

In a statement to Reuters Health, Fitbit said its trackers show an estimated total number of calories. “Fitbit uses a scientifically validated estimate of (basal metabolic rate) based on height, weight, age, and gender information that users provide when setting up their Fitbit account,” said the statement, which added that the measure also takes into account people’s heart rates.

“While the Mio ALPHA 2 was designed for the individuals focused on heart rate zone training, and not for all-day activity tracking, we agree that more accurate calorie estimation is important for the industry as a whole, since most individuals are monitoring calorie deficits for weight loss,” said Mark Gorelick, chief science officer at Mio Global, in a statement.

Markku Lankinen, who is head of operations for PulseOn Oy, said in an email that the researchers may not have adjusted the device specifically for each participant. “With PulseOn device, you would need to apply these user parameters in the application before exercising, and this seems not to have been done,” said Lankinen. “This causes the (energy expenditure) estimates to be badly off.”

Apple, Microsoft and Samsung did not provide comments for publication. All Basis Peak watches were recalled in 2016 due to overheating, according to its website.

Ashley’s team is currently conducting a study to test the accuracy of devices in the real world.

Grill Safety: 15 BBQ Hazards That Could Spoil Your Memorial Day Holiday

by Dr Alex Jimenez | Diets, Fitness

It’s time to bring out the outdoor grill, clean it up, and start preparing memorable meals this weekend. But experts warn that grilling can be dangerous to your health if you don’t take some basic precautions.

“I love how food tastes when it’s prepared on a grill,” says renowned chef Gerard Viverito, an associate professor in culinary arts at the Culinary Institute of America in Hyde Park, NY.

“It’s so much fun to create a meal outdoors with family and friends nearby. But while outdoor cooking is an American tradition, common mistakes, such as marinating with the wrong oil, and improper preparation and storing of food, can lead to disaster.”

Gerard, a well-known radio and television figure whose culinary emphasis is using nutritional ingredients to gain healthful results, tells Newsmax Health the key to a happy, and healthy holiday meal, involves careful planning. Here are his tips:

Before you grill:

• Thaw meat in the refrigerator. Defrosting food on the counter encourages the growth of disease causing pathogens such as listeria and salmonella.
• Thaw proteins completely before grilling. “That’s the best way to ensure your food cooks evenly,” says Gerard. “Use a meat thermometer in the thicket part to ensure doneness.” Healthy internal temperatures are: poultry, 180 degrees; burgers, 160 degrees; pork 160 degrees; and steaks, 145 for medium rare and 160 degrees for medium.
• If you are marinating, avoid using olive oil which can break down at high temperatures into dangerous carcinogens. Gerard prefers using Malaysian sustainable palm oil that can stand up to high heat.
• Wash your hands thoroughly before transferring food to the grill.

Cooking with charcoal or propane:

• To avoid inhaling smoke and help prevent accidental fire, position the grill away from your house, and out from under eaves and tree branches. Each year, home grilling is responsible for thousands of home fires and burns that require hospital care.
• Start with a clean grill. A buildup of extra grease and fat can cause a flash fire, in addition to contaminating your food with potential carcinogens.
• Only use charcoal starter fluid with a charcoal grill. Stay safe by never adding flammable fluid once a fire has started. And if your grill does catch fire, the safest way to extinguish the flame is to close the top of the grill and turn off the gas.
• Keep meat and vegetables separate on a grill. You want to keep meat drippings from falling on your vegetables. “That’s because vegetables don’t cook long enough to destroy any bacteria present in the drippings,” says Gerard.

Serving your food:

• Always transfer cooked food onto a clean latter. Don’t use the same plate that you just used for the raw food.
• Keep food hot until it’s served. Move it off the fire but keep it on the warm grill or use a hot plate. Hot Logic hotlogicmini.com/collections/buy-now, a Michigan-based company, produces a series of low-cost covered hot plates and mini ovens that can keep food warm until it’s ready to be eaten. “Very hot food and very cold food is the safest, but since most people like to eat foods somewhere in the middle, this can be a problem,” says Gerard. “We call it the temperature danger zone where bacteria multiply exponentially.”
• Throw away any burned or charred portions before eating. The char and soot may contain dangerous chemicals or carcinogens.
• Keep flies away from food. Use food covers to keep insects from sharing your meal and spreading germs.

Treat leftovers with care:

• Refrigerate leftovers as soon as possible to reduce the risk of food spoilage and poisoning.
• Discard food that’s been sitting out for two hours or more. “I go crazy when I see people eating potato salad made with mayonnaise that’s been left outside for hours,” says Dr. Kevin Rodgers, president of the American Academy of Emergency Medicine. “Don’t take a chance if food safety is questionable. Food poisoning can cause serious dehydration through vomiting and diarrhea.”
• Don’t eat unwashed fruits or veggies. “It’s also important to wash all produce, like those tasty tomatoes you are serving over the burgers or the salad greens,” warns Gerard. “The Centers for Disease Control and Prevention reveals that salad greens caused 8,838 cases of food borne illness between 1998 and 2008, so always be diligent in washing lettuce, escarole, spinach, cabbage, kale and arugula before serving.”

“Grilling is fun and delicious,” says Gerard. “With a few precautions, you can keep food-borne pathogens, fires, and exposure to carcinogens from spoiling one of best warm weather pastimes.”

For Healthier Arteries, Eat More Fruits and Veggies

by Dr Alex Jimenez | Diets, Fitness

Eating more fruits and vegetables may reduce the risk of peripheral artery disease, according to a study of more than 3.6 million individuals in the U.S.

“We hope that studies like this can be an important reminder of the role we as consumers have on heart disease and stroke,” Dr. Jeffrey S. Berger from New York University School of Medicine told Reuters Health. “We often remember to take our medication, yet studies like this should remind us to eat our fruits and veggies every day. Moreover, we should continue reminding our young generation of this importance now before disease develops.”

Past research has linked fruit and vegetable consumption to a lower risk of coronary heart disease and stroke, but there has been little research into the effects of fruits and vegetables on arteries in the legs and arms, Berger’s team writes in Arteriosclerosis, Thrombosis, and Vascular Biology.

Peripheral artery disease, or PAD, usually arises as a narrowing of arteries to the legs that causes cramping, pain or tiredness in the muscles while walking or climbing stairs. It affects at least 8 to 12 million Americans.

Risk for PAD increases with age, and with a history of smoking, diabetes or high blood pressure.

To investigate whether fruit and vegetable consumption influences risk for PAD, Berger’s team analyzed dietary data on 3,696,778 men and women with an average age of about 65, around 234,000 of whom had PAD.

The U.S. Department of Agriculture/U.S. Health and Human Services Dietary Guidelines for Americans recommend at least two servings of fruit and at least three servings of vegetables each day, but only 29 percent of participants in the study said they ate even three servings of fruits and vegetables daily.

Nearly half said they consumed at least three servings of fruit and vegetables on fewer than half the days of the week.

Older white women were most likely to consume fruits and vegetables regularly, and younger black men were least likely to eat at least three servings daily.

Fruit and vegetable consumption also varied by region, with those living in the Pacific states reporting the most regular consumption and those living in the South Central states reporting the least regular consumption.

After adjusting for age, sex, race and other risk factors, the more fruits and vegetables the participants ate, the lower their likelihood of having PAD.

When researchers divided participants according to their smoking status, they found the relationship between fruit and vegetable intake and PAD was strongest among current smokers, less significant among former smokers and not significant among people who never smoked.

“Unfortunately, fruit and vegetable intake is quite low across the entire United States,” Berger said by email.

“Something as simple as eating fruits and vegetables could have a major impact on the prevalence of a life-altering disease, such as peripheral artery disease,” he said.

“Watch what you eat,” Berger advised. “And pay careful attention to eat fruits and vegetables every single day.”

“Increasing fruit and vegetable intake is important and can have far reaching health benefits,” said Dr. Michelle L. Redmond from University of Kansas School of Medicine-Wichita, who wasn’t involved in the study.

To get people to up their intake of greens, she said by email, “First, one must take into consideration factors that influence behaviors such as access and affordability of fresh fruits and vegetables (how do you change or lessen certain barriers to fruit/vegetable intake). Then design interventions or campaigns that are tailored to specific audiences to motivate and increase fruit/vegetable consumption. Finally, there is also a need to increase nutrition literacy.”

Getting people to eat more fruits and vegetables is a challenge in other countries, too, noted Dr. Miguel A. Martinez-Gonzalez from University of Navarra Medical School in Spain, who wasn’t involved in the study. He acknowledged the special importance of fruit and vegetable consumption for smokers but, he told Reuters Health, “This advice should be given to everybody.”