Fad diets can work, but experts find no magic slimming bullet

January 13, 2014

Resolutions to lose weight are often made in January yet almost as frequently abandoned as heavy hopefuls find diets that demand fasting, virtually no carbs or liquid food shakes notoriously hard to stick to. But even "fad" diets can lead to a slimmer, lighter New Year for those whose resolve remains robust, according to doctors and nutritionists analysing them.

Gathering for a London conference to review evidence behind popular weight loss diets - at just the time of year when slimming ideas are in peak demand - specialists concluded that food fads such as the hunter-gatherer "Paleo" plan or the 5:2 diet can deliver. But it's hard work. "If it was easy, our species would have died out years ago. As humans we have a default to eat," said Gary Frost, a professor and chair of nutrition and dietetics at Imperial College London. The results of that default are looming large in a global "wave of obesity", he said. According to the World Health Organisation, worldwide obesity - defined as having a body mass index of more than 30 - has nearly doubled since 1980. The latest global figure is that in 2008, more than 1.4 billion adults were overweight.

WAVE OF OBESITY

According to the US Centers for Disease Control and Prevention, almost 36% of American adults are obese and almost 70% are either obese or overweight. In Britain, a government health study predicts 60% of men, 50% of women and 25% of children will be obese by 2050. Against this background, experts say the search for effective diets must always take account of how easy it is for people to understand and follow, and how likely they are to abide by its restrictions.

Michelle Harvie, a research dietician from the Genesis Prevention Centre at Britain's University Hospital of South Manchester, said that on this front, fasting diets - sometimes called intermittent diets - can be successful. "Energy restriction is difficult to maintain over the long term and people tend to find it easier to follow a diet with intermittent energy restriction," she said. She said that while a regular weight loss plan might require the dieter to take in 25% fewer calories, intermittent diets may suggest two days of a 75% calorie cut interspersed with five days of normal healthy eating. But the key to these diets - such as the 5:2 diet in which followers eat as little as 400 calories on two "fasting" days per week - is that dieters won't succeed if they "pig out" and eat whatever they want on non-fasting days.

Harvie's research shows those who succeed in losing weigh on these diets find the fasting days lead them to also have a lower food intake on normal days - leading to lower calorie intake overall.

HUNTING FOR FOOD

Mark Berry, head of plant biology and biochemistry at the consumer company Unilever's research and development unit, says there are also positive signs in data from studies of "Palaeolithic" or stone-age diets - plans designed to mimic the diet of pre-agricultural hunter-gatherers of that era. A sign of its current popularity is that "Paleo diet" was one of the most "Googled" terms of 2013.

The idea is based around foods that can be hunted, fished or foraged for - meat, seafood, eggs, nuts, seeds, fruits and vegetables. Berry said his research showed little impact on glucose response in the body in people eating a Palaeolithic diet, but did find a significant impact on hormones that signal satiety and tell the brain the eater is full. Alexandra Johnstone of the Rowett Institute of Nutrition and Health, who has been looking into high protein and low carbohydrate diets such as the Atkins diet, said these also had a significant impact on fullness feelings - giving them the potential to help dieters control appetite and lose weight. "The high satiety effects of increased protein in the diet seems to be a contributing factor to the success of high-protein, low-carbohydrate diets," she said.

Johnstone cited data showing the amount of weight lost on high-protein diets is around double that lost on a comparable low-fat diet at the six-month mark. But there is little difference in weight loss after one year, as dieters often lose momentum and their resolve to slim down fades. "There's no magic bullet," she said. Judy Buttriss, head of the British Nutrition Foundation, said the evidence for popular diets was clearly nuanced. While there are several that can be used as tools for effective weight loss and maintenance, she said "there's currently no evidence that one is any better than another in the long term".

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Agencies
January 26,2020

High-protein diets may help people lose weight and build muscle, but there is a downside to it --a greater heart attack risk. Researchers now report that high-protein diets boost artery-clogging plaque.

The research in mice showed that high-protein diets spur unstable plaque -- the kind most prone to rupturing and causing blocked arteries.

More plaque buildup in the arteries, particularly if it's unstable, increases the risk of heart attack.

"There are clear weight-loss benefits to high-protein diets, which has boosted their popularity in recent years," said senior author Babak Razani, associate professor at Washington University School of Medicine in St. Louis, Missouri.

"But animal studies and some large epidemiological studies in people have linked high dietary protein to cardiovascular problems. We decided to take a look at whether there is truly a causal link between high dietary protein and poorer cardiovascular health," Razani added.

The researchers studied mice who were fed a high-fat diet to deliberately induce atherosclerosis, or plaque buildup in the arteries.

Some of the mice received a high-fat diet that was also high in protein. And others were fed a high-fat, low-protein diet for comparison.

The mice on the high-fat, high-protein diet developed worse atherosclerosis -- about 30 per cent more plaque in the arteries -- than mice on the high-fat, normal-protein diet, despite the fact that the mice eating more protein did not gain weight, unlike the mice on the high-fat, normal-protein diet.

"A couple of a scoop of protein powder in a milkshake or smoothie adds something like 40 grams of protein -- almost equivalent to the daily recommended intake," Razani said.

"To see if protein has an effect on cardiovascular health, we tripled the amount of protein that the mice receive in the high-fat, high-protein diet -- keeping the fat constant. Protein went from 15 per cent to 46 per cent of calories for these mice".

Plaque contains a mix of fat, cholesterol, calcium deposits and dead cells. Past work by Razani's team and other groups has shown that immune cells called macrophages work to clean up plaque in the arteries.

But the environment inside plaque can overwhelm these cells, and when such cells die, they make the problem worse, contributing to plaque buildup and increasing plaque complexity.

"In mice on the high-protein diet, their plaques were a macrophage graveyard," Razani informed.

To understand how high dietary protein might increase plaque complexity, Razani and his colleagues also studied the path protein takes after it has been digested -- broken down into its original building blocks, called amino acids.

"This study is not the first to show a telltale increase in plaque with high-protein diets, but it offers a deeper understanding of the impact of high protein with the detailed analysis of the plaques," said Razani.

"This work not only defines the critical processes underlying the cardiovascular risks of dietary protein but also lays the groundwork for targeting these pathways in treating heart disease," he added.

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Agencies
April 4,2020

Washington D.C., Apr 4: While consuming a high-diet salt can result in high blood pressure, a recent study has revealed a link between salt-rich diet and weaker immune system.

The study was conducted under the leadership of the University Hospital Bonn, and the results were published in the journal Science Translational Medicine.

The research was conducted on mice that were fed a high-salt diet. Later, they were found to suffer from much more severe bacterial infections.

Human volunteers who consumed an additional six grams of salt per day also showed pronounced immune deficiencies.

The World Health Organization (WHO) has recommended a maximum amount of five grams of salt a day.

It corresponds approximately to one level teaspoon. In reality, however, many Germans exceed this limit considerably. 

Figures from the Robert Koch Institute suggest that on average men consume ten, and women more than eight grams a day.

This means that we reach for the salt shaker much more than is good for us. After all, sodium chloride, which is its chemical name, raises blood pressure and thereby increases the risk of heart attack or stroke.

"We have now been able to prove for the first time that excessive salt intake also significantly weakens an important arm of the immune system," said Prof. Dr. Christian Kurts from the Institute of Experimental Immunology at the University of Bonn.

This finding is unexpected, as some studies point in the opposite direction. For example, infections with certain skin parasites in laboratory animals heal significantly faster if these consume a high-salt diet.

The study also sheds light on the fact that the skin serves as a salt reservoir.

"Our results show that this generalization is not accurate," emphasized Katarzyna Jobin, lead author of the study.

The body keeps the salt concentration in the blood and in the various organs largely constant. Otherwise important biological processes would be impaired. The only major exception is the skin which functions as a salt reservoir of the body. This is why the additional intake of sodium chloride works so well for some skin diseases.

However, other parts of the body are not exposed to the additional salt consumed with food. Instead, it is filtered out by the kidneys and excreted in the urine.

"We examined volunteers who consumed six grams of salt in addition to their daily intake," said Prof. Kurts. This is roughly the amount contained in two fast-food meals, i.e. two burgers and two portions of French fries.

After one week, from the results, it showed that the immune cells coped much worse with bacteria after the test subjects had started to eat a high-salt diet.

In human volunteers, excessive salt intake also resulted in increased glucocorticoid levels.

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News Network
May 11,2020

Panaji, May 11: Amid the COVID-19 outbreak, most of the people are more concerned about the health of their near and dear ones than their own well-being, says a study conducted by a leading business school in Goa.

People are now more conscious about any bodily changes, and even mild cold, cough and sneezing, it says.

The study, on public's reaction towards COVID-19 outbreak by gauging their psychological response in terms of anxiety and their coping behaviour, was conducted by the Goa Institute of Management's Dr Divya Singhal and Prof Padhmanabhan Vijayaraghavan.

It took into account inputs from 231 respondents residing in various parts of the country.

"Nearly 82.25 per cent of the respondents were more worried about the health of their loved ones than their own well-being," Singhal said.

"Majority of the respondents have become conscious of any bodily changes, sensations, a mild cold, cough, sneezing and experience concern, and attribute those changes to the symptoms of COVID-19," she said.

Besides, more than 50 per cent of the respondents said their social media usage has gone up as well as their time spent on watching movies and shows through online medium, the official said.

The respondents agreed that their technology usage to connect with friends and relatives has gone up, she said.

The study also indicated that a large group of respondents found it "depressing" to read forwarded messages on the deadly disease.

"An overwhelming majority of the respondentsagreed that they discourage unverified forwarded messages about COVID-19 on social media," says the study.

It also found that 41 per centof the respondents were not doing any physical activity, like yoga, during the lockown period, while another 19 per cent were not sure about engaging themselves in physical activities.

Besides, 57 per cent of the respondents were not engaged in any mind-calming practices like meditation, and 18 per cent were not sure about taking up meditative practices, the study said.

The respondents included 145 men and 86 women, aged 18 and above, with nearly 60 per cent of them residing in non- metro cities and rest from metros.

About 47.62 per cent of the respondents were employed in private or government sectors, and the remaining included students, retired persons and homemakers.

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