Diet and Weight-Loss FIndings
Fat-filled diets and hunger-curbing injections may sound like fads, but in 2016, new research suggested that such interventions could have health and weight-loss benefits.
Here are seven studies from 2016 that highlight some of the most intriguing diet and weight-loss findings of the year
Dieting actually improves your mood.
Think you'll be "hangry" if you go on a diet? Think again: A study published in the journal JAMA Internal Medicine found that when people who were normal weight or overweight (but not obese) cut calories, they slept better, were in a better mood and had better sex lives.
In the study, researchers looked at 220 people who were divided into two groups: a calorie-restricted group advised to cut their daily calorie intake by about 25 percent, and a control group that received no dietary advice. Researchers tracked the participants for two years, asking them to periodically fill out questionnaires about their mood, quality of life, sexual function and sleep.
"We found that normal-weight and mildly overweight people who wish to lose weight need not worry about decreased quality of life," Corby Martin, director of the Ingestive Behavior Laboratory at the Pennington Biomedical Research Center in Louisiana and the lead author of the study, told Live Science in May.
Instead, "they can actually expect to feel better," Martin said. Another benefit? The participants in the calorie-restricted group lost an average of about 17 lbs. (8 kilograms) over the two-year period, compared with almost no weight change in the control group.
There could be an exercise "sweet spot" for losing weight.
What's the optimal amount of exercise to do if you want to lose weight? A study published in the journal Current Biology may provide some clues: Researchers found that people who engaged in moderate levels of physical activity burned about 200 more calories per day than those who had the lowest levels of physical activity. However, strikingly, the people who were the most physically active burned, on average, the same number of calories as those who were moderately active.
This may be because the body adapts to higher levels of activity, study author Herman Pontzer, an associate professor of anthropology at the City University of New York, told Live Science in January. Exercising a lot may actually prompt the body to make adjustments to adapt and actually keep its energy expenditure at the same level as it does when exercising less, the researchers concluded.
Injections of tiny beads could promote weight loss.
In a small study presented at the Society of Interventional Radiology's annual meeting this year, researchers described a new procedure that may curb feelings of hunger and promote weight loss.
In the procedure, called bariatric arterial embolization, microscopic beads are injected into the blood through a tiny nick in the wrist or groin. The beads travel to a part of the stomach called the fundus, where they decrease the amount of blood flow to that area. The fundus produces most of the body's ghrelin, also known as the hunger hormone, so by decreasing blood flow to the area, the procedure may limit the amount of ghrelin the fundus secretes, the researchers said.
Study lead author Dr. Clifford Weiss, director of interventional radiology research at the Johns Hopkins University School of Medicine, noted in a statement that the doctors who completed the study are excited about the possibilities the procedure offers. Compared to weight-loss surgery, this procedure "is significantly less invasive and has a much shorter recovery time," he said.
However, the findings have not yet been published in a peer-reviewed journal, and much more research will be needed to confirm the procedure's safety and effectiveness.
Eating fat doesn't make you fat.
A study published in the journal The Lancet Diabetes & Endocrinology found that men and women who followed a high-fat, Mediterranean diet that was rich in either olive oil or nuts lost more weight and reduced their waist circumference more than people who were instructed to reduce their fat intake.
In the study, researchers used data gathered over a five-year period on people in Spain, as part of a study that examined the effects of the Mediterranean diet on heart health. The study included almost 7,500 older adults who were instructed to follow one of three diets: a Mediterranean diet with at least 4 tablespoons of extra-virgin olive oil each day, a Mediterranean diet with at least three servings of nuts each week, or a control diet in which the participants were advised to generally avoid consuming fat.
After five years, the people in both the olive-oil group and the nut group lost more weight than the control group, and also greater reductions in their waist circumferences when compared with the control group.
The key takeaway is that neither fat-rich diet led to weight gain or increases in weight, lead study author Dr. Ramon Estruch, an internal medicine physician at the University of Barcelona in Spain, told Live Science in June.
Plant protein may keep you full longer than meat does.
A recent study published in the journal Food and Nutrition Research found that plant protein may be more effective than animal protein at making you feel full and helping you eat less at your next meal.
In the study, 43 young male participants ate one of three different breakfast meals, on three different days, each two weeks apart. The first was a high-protein meat patty with a potato mash, the second was a high-protein legume patty with a split-pea mash, and the third was a low-protein legume patty with a potato mash. (Legumes are a plant group that includes beans and lentils.)
The men reported feeling fuller after eating the high-protein legume-patty meal than they did after eating each of the other two meals.
In addition, the participants who consumed the high-protein legume patty consumed 12 to 13 percent fewer calories at lunch compared with when they had consumed either of the other two patties for breakfast, senior study author Anne Raben, a professor of obesity research at the University of Copenhagen, told Live Science in November. One reason for this may have been the higher amount of fiber in the high-protein legume patty, the researchers noted.
Probiotics help lower blood sugar levels.
In the study, some people who were following the DASH (Dietary Approaches to Stop Hypertension) diet, which is recommended for people with high blood pressure, were asked to eat probiotics as well. The people who consumed probiotics over the three-month study period had a larger average decrease in several measures of blood sugar levels than the group that only followed the DASH diet and did not take probiotics.
Although more research is needed, the findings suggest that adding probiotics to the DASH diet could help protect against diabetes, said the study's author, Arjun Pandey, a researcher at the Cambridge Cardiac Care Centre in Ontario.
One possible explanation for the findings may relate to a compound called butyrate, which is produced in the gut by certain bacteria and plays a role in insulin sensitivity, Pandey told Live Science in November. Increased levels of butyrate may lead to higher insulin sensitivity, thus leading body cells to absorb sugar from the blood more efficiently and, in turn, decrease blood sugar levels, he said.
The findings were presented at the American Heart Association's Scientific Sessions annual meeting in November and have not been published in a peer-reviewed journal.
Working out before breakfast may help you eat less.
If you're looking to lose weight, try working out before breakfast: A small study published in the Journal of Nutrition and Metabolism suggests that skipping breakfast before your workout may help you consume fewer calories throughout the day.
In the study, 12 physically active, young white males were assigned to one of two groups: One group was given oatmeal and orange juice for breakfast, and the other group was given no breakfast. At 10 a.m., the men ran on a treadmill for an hour. Then, the men were given food to take with them and were instructed to eat as much as they wanted for the rest of the day. The researchers measured the amount of food left over. After one week, the men repeated the experiment, but the groups were switched.
The researchers found that the men consumed many more calories overall on days when they ate breakfast before exercising: The participants consumed an average of 4,500 calories on days when they ate breakfast before exercising, but an average of only 3,600 calories on days when they fasted before exercising, the study's lead author, Jessica Bachman, an assistant professor of exercise science at the University of Scranton in Pennsylvania, told Live Science in October.
Most of these calories were consumed in the evening, Bachman added. However, the study looked at a very small, homogenous group, so the researchers cautioned that more studies are needed to confirm the findings and apply them to different groups of people.