Monthly Archives: February 2017

How Sugar Drink Can Make Your Body Stretch Burn Fat

Washing down your bacon cheeseburger with a big, cold soda may trigger the body to store more fat than it would if you drank something without sugar, a new small study finds.

When the people in the study added a sugary drink to a protein-rich meal, their bodies’ fat-burning ability decreased by 8 percent on average, the researchers found. In addition, the sugary drinks also appeared to increase their food cravings after the meal.

“We were surprised by the impact that the sugar-sweetened drinks had on metabolism when they were paired with higher-protein meals,” lead study author Shanon Casperson, a research biologist at the U.S.  Department of Agriculture’s Agricultural Research Service, said in a statement. [11 Ways Processed Food is Different from Real Food]

“This combination also increased study subjects’ desire to eat savory and salty foods for four hours after eating,” Casperson added.

Indeed, earlier research has shown that people who increase their protein intake experience changes  both in how food is processed by their body and in how much they eat, according to the study, published July 20 in the journal BMC Nutrition. For example, research suggests that a higher protein intake is linked to an increase in the body’s fat-burning abilities.

The new findings suggest that adding sugary drinks to a high-protein intake may have the opposite effect: The sugar-rich beverages may slow the body’s burning of fat, according to the study.

For the study, the researchers recruited 27 healthy young adults, gave them special meals and then observed them in special isolated rooms called “room calorimeters.”  The rooms had a bed, a toilet, a sink and some other furniture, and equipment to measure the levels of oxygen and carbon dioxide along with temperature and air pressure. These measurements allowed the researchers to calculate how the foods the participants ate affected their metabolism, including how many calories they burned and how they broke down fat, protein and carbohydrates.

The participants spent two 24-hour periods in the rooms. Each period started at 4 p.m., and each participant had dinner at 5 p.m. in the chamber. The participants then fasted until breakfast the next morning. [8 Reasons Our Waistlines Are Expanding]

Then, the experiment really began. During one stay in the room, the participants were served breakfast and lunch meals that each contained 15 percent protein. Each meal was served with a sweet drink that contained either sugar or an artificial sweetener. If the drink with sugar was served at breakfast, the participant received the artificially sweetened drink at lunch, and vice versa. This allowed the researchers to see if there was any difference between how the meal was metabolized when it was combined with sugar, versus without sugar.

After both breakfast and lunch, the participants were observed for 4 hours. During this time, the researchers could see how the body responded to the meal with either a sugary drink or an artificially sweetened drink.

During their other stay in the room, the participants were served breakfast and lunch meals that each contained 30 percent protein.

The researchers found that when a sugar-sweetened beverage was served with a meal, the participants’ fat-burning ability was 8 percent lower than it was when the meal was served with an artificially sweetened drink. In addition, although the sugary drinks added more calories to the meals, they didn’t cause the participants to feel fuller after eating.

In other words, sugary drinks seem to decrease the body’s fat burning and don’t contribute to feeling fuller. The findings “provide further insight into the potential role of sugar-sweetened drinks — the largest single source of sugar in the American diet — in weight gain and obesity,” Casperson said.

Be careful with the Birth Control App, Expert Say

A new smartphone app has been approved for people to use as a type of contraception in the European Union, but experts warn that you shouldn’t toss out the condoms and birth control pills just yet.

The app, Natural Cycles, is available in the Apple App Store and the Google Play store to users everywhere. It digitizes an age-old method of preventing pregnancy, sometimes called the rhythm method, natural family planning or fertility awareness. The idea is to track ovulation and avoid sex (or use additional protection) on days when a woman is most likely to be fertile. But these methods have a failure rate of about 25 percent, even though the promotional materials for Natural Cycles claim that the app is 93 percent effective. [Wonder Woman: 10 Interesting Facts About the Female Body]

“Don’t rely on something like this,” said Dr. Mary Jane Minkin, a professor of obstetrics, gynecology and reproductive sciences at the Yale School of Medicine who is not involved with the company that makes the app. The app could be an option if a couple wanted to postpone pregnancy for a while but would not mind it if they did become pregnant, she said. But most people who are looking for contraception are going to want something more reliable.

The company that makes Natural Cycles is headquartered in Sweden, and the app was certified as a medical device in February, making it the only app that can call itself “contraception” in Europe. The app requires users to enter a precise body-temperature measurement first thing every morning — a familiar task for people who are already using natural family planning methods, as resting body temperature rises by a miniscule amount right at ovulation. The app then tracks body temperature and the menstrual cycle, taking into account the amount of time that sperm are likely to survive in the body, to give “red” days on which the chance of fertilization is high and “green” days on which it is lower.

It’s essentially just the tech-age way of doing natural family planning, “which has been around for generations,” said Dr. Nathaniel DeNicola, an assistant professor of obstetrics and gynecology at The George Washington University’s School of Medicine & Health Sciences. DeNicola is not involved with the company that makes the app.

But the success rate that Natural Cycles touts seems unrealistically high, and it comes from just two clinical studies, DeNicola said. Research on other methods of contraception — including condoms, birth control pills and intrauterine devices (IUDs) — goes back decades, so the success rates are pretty clear. That’s not true of this app, DeNicola said.

In one study, a clinical study published in March 2016, the app’s makers found that it had a failure rate of just 0.5 percent — it accidentally gave users a green “go ahead” sign that unprotected sex would be OK on days when it should have given a red “no-go” sign only 0.5 percent of the time. In other words, out of 1,000 women using the app, 5 could expect to become pregnant due to the app’s algorithm failure.

This failure rate is on a par with that of one of the most reliablereversible birth control methods out there, the IUD, DeNicola said. However, that rate is the app’s “perfect use rate,” meaning it applies only to people who use the app perfectly, following the directions to the letter every day, DeNicola said.

The perfect-use rate is “probably the last number that should be out there, because the data really isn’t close to supporting that” for typical users, DeNicola said. [7 Surprising Facts About the Pill]

Another estimate of the app’s failure rate is called the “typical use” rate, and pegs the risk of an unintended pregnancy at 7 percent. But that number is based on a single study in which a third of the people enrolled dropped out before the end. The company-affiliated researchers did a more conservative calculation by assuming all of those dropouts got pregnant, and came to a failure rate of 10 percent.

“That would probably be the most medically sound number to be talking about, if you felt comfortable giving a number at all based on just one study,” DeNicola said.

Whether Natural Cycles would be a good choice depends on the user’s needs and expectations for their birth control, Minkin said. If the 25 percent chance of pregnancy that normally comes with the natural family planning method seems acceptable, then the app is “certainly better than nothing,” she said.

But anyone hoping for a more reliable method should not go in thinking that Natural Cycles, or any fertility awareness app, will give them a 99.5 percent chance of not getting pregnant, DeNicola said. For rates like that, people would be better off using long-acting reversible contraceptives, or LARCs. These include options such as the birth control implant that goes under the skin (99 percent effective, according to Planned Parenthood) and IUDs (99 percent effective).

At present, health and medicine apps are largely unregulated in the United States, said DeNicola, who is the vice chair of the American Congress of Obstetricians and Gynecologists’ task force on telehealth. That means that the safety and efficacy of health apps are often “buyer beware.”

Why Hunger Can Eliminate If You Ignore It Long?

Why is it that when you’re tremendously hungry, you’re able to forget about it if you’re in the middle of an intriguing activity, such as reading a good book?

It’s almost as if you’re able to ignore those hunger pangs until your task is complete, at which point the hunger can hit you hard.

Such a question might seem straightforward, but the answer is actually quite complex and perplexing, dietitians told Live Science. [Why Do Your Teeth Feel Weird After Eating Spinach?]

When a person is hungry, a cascade of triggers notifies the brain that the body needs food. One of those triggers is a hormone called ghrelin — “the only mammalian substance that has been shown to increase appetite and food intake when delivered to humans,” according to a 2006 review in the journal Physiology and Behavior.

Most of the body’s supply of ghrelin is created in the stomach and duodenum (the first part of the small intestine). Once made, ghrelin can cross the blood-brain barrier and target certain parts of the brain, stimulating hunger, according to the review.

Moreover, ghrelin is with us 24/7: its levels drop as we eat, and rise before meals, reaching concentrations high enough to stimulate hunger, according to the review.

However, a curious finding shows that ghrelin isn’t the be-all and end-all of hunger pangs.

In a 2016 study in the journal Clinical Nutrition, 59 obese adults participated in an eight-week-long program in which they fasted every other day. (They ate sparingly on the “fast” days, and ate freely on alternate days.) But after measuring the participant’s ghrelin levels, the researchers found that “hunger was not related to ghrelin concentrations … at any point,” they wrote in the study.

In other words, when people fasted, their levels of ghrelin increased. But for unknown reasons, these people didn’t report feeling hungrier than usual.

“It’s interesting because the subjective “How hungry are you?” doesn’t really match up with what we measure clinically,” Colleen Tewksbury, a bariatric program manager at Penn Medicine, who was not involved with the review or the study, told Live Science.

So, why is it that people can basically ignore their hunger pangs? One idea, based on anecdotal observations, is that intense activities can distract people from their hunger, said Leah Groppo, a clinical dietician at Stanford Health Care in Palo Alto, California.

“If you’re really distracted, oftentimes people are able to lose that sense of hunger,” Groppo told Live Science. “Then, over time it [the feelings of hunger] will diminish because you’re still hyper-focused on something else.”

However, if you’re surrounded by enough cues to remind you of your hunger — say, you’re reading a novel but you’re by the kitchen, and the smell of dinner is wafting through the air — then you’ll likely remember how hungry you are.