Why it really is harder for women to lose weight – The Washington Post

Just a blurb. Read on (and don’t be afraid to “train like a man”)

First, there is the matter of muscles and metabolism. Men tend to have more muscle than women, and because muscle burns more calories than fat, men tend to have a faster metabolism, too — anywhere between 3 to 10 percent higher than women, studies have shown.

And at the gym, that difference just gets exacerbated. Women, worried about bulking up, tend to lift lighter weights and focus more on cardiovascular fitness, while men tend to gravitate toward the kind of heavy lifting that boosts muscle composition and metabolic rate, says Jim White, a Virginia Beach-based nutrition expert and certified personal trainer.

When it comes to food, there is evidence that men and women’s brains are wired differently.via Why it really is harder for women to lose weight – The Washington Post.

Fast Weight Loss May Mean Muscle Loss – Healthday

Fast Weight Loss May Mean Muscle Loss

Study volunteers eating 500 calories a day lost more muscle than those eating more than twice as much

Fast Weight Loss May Mean Muscle Loss

THURSDAY, May 29, 2014 (HealthDay News) — If you lose weight too fast, you lose more muscle than when you shed excess pounds more slowly, a small study says.

The researchers put 25 participants on a five-week very-low-calorie diet of just 500 calories per day. Another 22 volunteers went on a 12-week low-calorie diet of 1,250 calories per day.

The investigators found that right after the end of their diets, both groups had similar levels of weight loss. The average weight loss was a little over 19 pounds among those on the very-low-calorie diet and just under 19 pounds among those on the low-calorie diet.

The researchers then looked at the loss of fat-free mass, which includes all the tissue in the human body, except fat. The major tissues are blood, bones, organs and muscles. However, the mass of the organs, blood and bones does not change during dieting. Therefore, changes in fat-free mass during dieting are mainly due to changes in muscle mass.

Participants on the very-low-calorie diet had lost about 3.5 pounds of fat-free mass, compared with 1.3 pounds among those on the low-calorie diet. Fat-free mass accounted for 18 percent of weight loss in the very-low-calorie diet group and 7.7 percent of weight loss in the low-calorie diet group, the study found.

Four weeks after the end of their diets, reductions in fat-free mass averaged 1.8 pounds among those in the very-low-calorie diet group and 0.7 pounds among those in the low-calorie diet group. Fat-free mass accounted for 9.4 percent of weight loss in the very-low-calorie diet group and 2.9 percent of weight loss in the low-calorie diet group, according to the report.

The findings were presented Wednesday at the European Congress on Obesity in Bulgaria.

“Loss of fat-free mass was higher after rapid than slow diet-induced weight loss with similar total weight loss,” said the study’s authors, Roel Vink and Marleen van Baak, of the School for Nutrition, Toxicology and Metabolism at Maastricht University in the Netherlands, and colleagues.

However, the authors also pointed out in a meeting news release that muscle loss among people in the very-low-calorie diet was likely overestimated immediately after they completed the diet, compared with four weeks later.

This is likely because they had a larger loss of water and glycogen (a natural form of sugar in the body) when they had just completed the diet than four weeks later, the researchers explained.

Research presented at meetings should be viewed as preliminary until it is published in a peer-reviewed medical journal.via Fast Weight Loss May Mean Muscle Loss.

Bacteria in the Intestines May Help Tip the Bathroom Scale, Studies Show

By The bacterial makeup of the intestines may help determine whether people gain weight or lose it, according to two new studies, one in humans and one in mice.

Philip Davis/Massachusetts General Hospital

The smaller mouse, right, lost weight after gastric bypass surgery, while the heavier ones, left, had “sham” operations.

Readers’ Comments

“As much as I hope for a breakthrough that would enable me to lose weight without changing my eating habits, I fear that such an innovation would doom the planet.”

Joe C from Austin, TX

The research also suggests that a popular weight-loss operation, gastric bypass, which shrinks the stomach and rearranges the intestines, seems to work in part by shifting the balance of bacteria in the digestive tract. People who have the surgery generally lose 65 percent to 75 percent of their excess weight, but scientists have not fully understood why. Now, the researchers are saying that bacterial changes may account for 20 percent of the weight loss.

The findings mean that eventually, treatments that adjust the microbe levels, or “microbiota,” in the gut may be developed to help people lose weight without surgery, said Dr. Lee M. Kaplan, director of the obesity, metabolism and nutrition institute at the Massachusetts General Hospital, and an author of a study published Wednesday in Science Translational Medicine.

Not everyone who hopes to lose weight wants or needs surgery to do it, he said. About 80 million people in the United States are obese, but only 200,000 a year have bariatric operations.

“There is a need for other therapies,” Dr. Kaplan said. “In no way is manipulating the microbiota going to mimic all the myriad effects of gastric bypass. But if this could produce 20 percent of the effects of surgery, it will still be valuable.”

In people, microbial cells outnumber human ones, and the new studies reflect a growing awareness of the crucial role played by the trillions of bacteria and other microorganisms that live in their own ecosystem in the gut. Perturbations there can have profound and sometimes devastating effects.

One example is infection with a bacterium called C. difficile, which sometimes takes hold in people receiving antibiotics for other illnesses. The drugs can wipe out other organisms that would normally keep C. difficile in check. Severe cases can be life-threatening, and the medical profession is gradually coming to accept the somewhat startling idea that sometimes the best therapy is a fecal transplant — from a healthy person to the one who is sick, to replenish the population of “good germs.”

Dr. Kaplan said his group’s experiments were the first to try to find out if microbial changes could account for some of the weight loss after gastric bypass. Earlier studies had shown that the microbiota of an obese person changed significantly after the surgery, becoming more like that of someone who was thin. But was the change from the surgery itself, or from the weight loss that followed the operation? And did the microbial change have any effects of its own?

Because it would be difficult and time-consuming to study these questions in people, the researchers used mice, which they had fattened up with a rich diet. One group had gastric bypass operations, and two other groups had “sham” operations in which the animals’ intestines were severed and sewn back together. The point was to find out whether just being cut open, without having the bypass, would have an effect on weight or gut bacteria. One sham group was kept on the rich food, while the other was put on a weight-loss diet.

In the bypass mice, the microbial populations quickly changed, and the mice lost weight. In the sham group, the microbiota did not change much — even in those on the weight-loss diet.

Next, the researchers transferred intestinal contents from each of the groups into other mice, which lacked their own intestinal bacteria. The animals that received material from the bypass mice rapidly lost weight; stool from mice that had the sham operations had no effect.

Exactly how the altered intestinal bacteria might cause weight loss is not yet known, the researchers said. But somehow the microbes seem to rev up metabolism so that the animals burn off more energy.

A next step, Dr. Kaplan said, may be to take stool from people who have had gastric bypass and implant it into mice to see if causes them to lose weight. Then the same thing could be tried from person to person.

“In addition, we’ve identified four subsets of bacteria that seem to be most specifically enhanced by the bypass,” Dr. Kaplan said. “Another approach would be to see if any or all of those individual bacteria could mediate the effects, rather than having to transfer stool.”

A second study by a different group found that overweight people may be more likely to harbor a certain type of intestinal microbe. The microbes may contribute to weight gain by helping other organisms to digest certain nutrients, making more calories available. That study was published Tuesday in the Journal of Clinical Endocrinology & Metabolism.

The study involved 792 people who had their breath analyzed to help diagnose digestive orders. They agreed to let researchers measure the levels of hydrogen and methane; elevated levels indicate the presence of a microbe called Methanobrevibacter smithii. The people with the highest readings on the breath test were more likely to be heavier and have more body fat, and the researchers suspect that the microbes may be at least partly responsible for their obesity.

This type of organism may have been useful thousands of years ago, when people ate moreroughage and needed all the help they could get to squeeze every last calorie out of their food. But modern diets are much richer, said an author of the study, Dr. Ruchi Mathur, director of the diabetes outpatient clinic at Cedars-Sinai Medical Center in Los Angeles.

“Our external environment is changing faster than our internal one,” Dr. Mathur said. Studies are under way, she said, to find out whether getting rid of this particular microbe will help people lose weight.

 

Eat Fat To Burn Fat | LIVESTRONG.COM

Put down the snackwells… here’s a great article why.

Eat Fat To Burn Fat | LIVESTRONG.COM

Eat Fat To Burn Fat | LIVESTRONG.COM.

For a long time, we thought avocadoes were good for nothing but ready-made guac and a decent California burger every now and then. But these little nutritional hand grenades were having an explosive impact on our diets for all that time. How so? They’re infused with a key nutrient for maintaining healthy weight: fat. 

Wait…fat can help us maintain our weight? Fat doesn’t make us fat? In a word: exactly.

Most of the fat that you eat—especially if you want to lose weight—should come from unsaturated sources, both monounsaturated (MUFA) and polyunsaturated (PUFA), Glassman says. Why? These good-for-you foods (like fish, seeds, nuts, leafy vegetables, olive oil, and, of course, avocadoes) pack tons of nutrients. Besides removing LDL cholesterol from arteries and promoting a healthier heart, unsaturated fat can help you burn fat big time without cutting calories. A 2009 study in the British Journal of Nutrition, found that participants who consumed the most unsaturated fatty acids have lower body mass indexes and less abdominal fat than those who consumed the least. Why? The unsaturated folks ate higher-quality foods. 

Read more: http://www.livestrong.com/article/557726-eat-fat-to-burn-fat/#ixzz21N0LBp1A