(Inside Science) — Did the ancient Egyptians eat like us? If you’re a vegetarian, tucking in along the Nile thousands of years ago would have felt just like home.
In fact, eating lots of meat is a recent phenomenon. In ancient cultures vegetarianism was much more common, except in nomadic populations. Most sedentary populations ate fruit and vegetables.
Although previous sources found the ancient Egyptians to be pretty much vegetarians, until this new research it wasn’t possible to find out the relative amounts of the different foods they ate. Was their daily bread really daily? Did they binge on eggplants and garlic? Why didn’t someone spear a fish?
A French research team figured out that by looking at the carbon atoms in mummies that had lived in Egypt between 3500 B.C. and 600 A.D. you could find out what they ate.
Scientists may have discovered a way of identifying dieters who are prone to piling the pounds back on after weight loss. A study at Maastricht University’s Department of Human Biology found a link between a gene involved in regulating blood pressure and post-diet weight gain in women. Women who regained weight after slimming had a high change in the concentration of a particular protein in their blood during dieting, research showed. Researchers now hope to develop a test to indicate how prone people are to yo-yo dieting.
Edwin Mariman, professor of functional genetics at Maastricht, said: “It was a surprising discovery, because until now there has been no clear link between this protein and obesity. “We do not yet have an explanation for the results, but it does appear that it should be possible within a few years to use this finding to develop a test to show who is at high risk of putting weight back on after a diet.”
Hospitals already conduct tests for the protein, known as the angiotensin I converting enzyme (ACE). But the test is currently carried out to check its activity in regulating blood pressure, rather than its concentration. Up 80% of dieters suffer from the yo-yo effect, returning to their original weight within a year.
The study looked at around 100 women aged 20 to 45, half of whom had maintained their post-diet weight and half of whom had put weight back on. The findings of the research have been published by Dr Ping Wang, a scientist in Professor Mariman’s research group, in the online scientific journal PloS ONE.
AN ad for La Parle Obesity Soap, absolutely guaranteed weight loss without diet or exercise. What on earth do you suppose the Norwood Chemical Company put in the soap? This obesity soap (used like ordinary soap) positively reduces fat without dieting or gymnastics. Absolutely harmless, never fails to reduce flesh when directions are followed. Maybe you eat it? Published in the July, 1903 issue of MODERN PRISCILLA.
Sources: MX, AP, Library of Congress, Magazine Art.org
OTHERWISE healthy teenage girls who diet regularly show worrying signs of malnutrition, Sydney researchers have found. The largest study of its kind shows pressure to be thin could be causing teenage girls serious harm, potentially preventing them from developing properly. The study of 480 girls, between 14 and 17, attending school in Sydney’s northern suburbs and on the central coast, found those who dieted often showed subtle but chronic signs of undernourishment compared to those who occasionally, or never, dieted. The girls were deficient in a number of nutrients and biochemicals, including calcium and protein, as well as haemoglobin, which is vital for transporting oxygen in the blood.
The study leader, Dr Ross Grant, said the teenagers were not getting the nutrients they needed to build their bodies. ”When you get through your adolescent years you should be the healthiest you are ever going to be, and these girls are not giving themselves the best chance to be healthy,” he said. Many students in the study were dieting even though, on average, they were not overweight. ”These are pretty much your average girls on the north shore. They are going to school and they are not unwell in any other way,” Dr Grant said. The low levels of calcium were particularly worrying, he said. ”Calcium is used as a signalling molecule for every cell in the body. If you are not getting enough calcium in your diet then your body starts to get it from wherever it can, which is the bones.”
Most researchers believe the amount of calcium consumed in a person’s teenage years sets the basic level available for the rest of their life. Media messages presenting excessively thin women as having an ideal body shape, or public health campaigns making girls overly aware of not consuming too many calories, could be to blame for dieting, said Dr Grant, who is the head of the Australasian Research Institute at the Sydney Adventist Hospital.
Christine Morgan, the chief executive of the Butterfly Foundation, an eating disorders advocacy group, said she was horrified, but not surprised, by the findings. ”Diets, by their very nature, are telling you to disregard your physiological appetite,” she said. ”These homespun diets result in us not putting the nutrients we need into our bodies.” Disordered eating – irregular eating behaviours that do not fall into the category of an eating disorder – had more than doubled in the past 10 years. ”It has become the norm,” Ms Morgan said.
A new study at the Children's Hospital of Philadelphia found that meal replacements like shakes, bars and prepackaged entrees aren't a good long-term solution for obese teens. For the new study, researchers randomly assigned 113 obese teens and their families to different diets for a year. One group of teens ate self-selected low-calorie meals not exceeding 1,300 to 1,500 total calories per day. The other group ate meal replacements (three SlimFast shakes and one prepackaged entree), along with five servings of fruits and vegetables. Four months into the study, participants in second group were randomized to a second-phase diet: some were put on the low-calorie self-selected diet, while the rest stayed on meal replacements.
At the four-month mark, all participants had lost weight, but the teens on meal replacements lost more — a 6.3% reduction in body mass index (BMI) versus 3.8% for the low-calorie group. But by the end of the one-year study, many participants had regained much of the weight they had lost, resulting in no significant differences in weight loss between the groups: on average, the teens had reduced their BMI 3.4% since the beginning of the study.
The results underscore one of the many difficulties of dieting: keeping the weight off long term. Many dieters regain weight because they can't stick to rigid eating programs for long: one-third of the participants in the current study dropped out before its conclusion. The monotony of the meal-replacement diet couldn't have helped either: teens in the meal-replacement group started out drinking SlimFasts 5.6 days a week (in Month 2); by the end of the study, they were only able to tolerate the shakes 1.6 days each week.
“The potential benefit of (meal replacement) in maintaining weight loss was not supported,” the researchers concluded. So for those of you who are gearing up to begin a weight-loss program in the New Year, it helps to remember that austerity isn't the best strategy long-term. Focus on variety — both with your diet and your exercise regimen — and manageability instead. A regular visit with Nastaran can ensure that you stay on track and keep the weight off long term.
FRANCE'S most popular weight-loss regimes, including the number one Dukan diet, are ineffective and potentially dangerous to people's health, doctors have warned. The Agence Nationale de Sécurité Sanitaire has issued a warning over 14 of the most fashionable diet regimes in France. Researchers at the Institut Pasteur in Lille assessed each regime, including Atkins and Montignac, for its nutritional value and potential side-effects. Head of nutritional research Jean-Michel Lecerf, who led the study, said the diets disrupted the body's natural metabolism and led to serious nutritional imbalances.
In nearly all the diets, the protein content was typically much higher than the recommended daily intake, especially the Dukan diet, which is France's top-seller. Some of the diets contained 10 times less fibre than the recommended level and up to twice as much salt. They also lacked vital vitamins and minerals. The study also pointed to an increased risk of fractures and other bone problems, muscle wastage and cardiovascular problems in some of the regimes.
Dr Lecerf said that in 95 per cent of cases, people who follow a dietary regime regain weight as soon as they finish. In some instances, the weight they regain is greater than the amount lost. He said: “Each regime is less effective than the one before, and the weight gain afterwards is greater each time.” According to the study, about 70 per cent of people in France have followed some sort of weight-loss programme, many without consulting a doctor beforehand.
The Régime Dukan is the most popular diet in France at the moment. Like Atkins, it is high in protein in the initial “attack” phase, but low in fat. Next comes the “cruise” phase, with protein-only days and protein-and-veg days. Potatoes are banned, as are high-calorie vegetables such as peas, carrots and sweetcorn.
More than two million copies of the Dukan book Je ne sais pas maigrir have been sold in France.
Throughout the project, the families received expert guidance from dietitians and were asked to provide blood and urine samples.
Diogenes: The five diet types
The design comprised the following five diet types:
- A low-protein diet (13% of energy consumed) with a high glycemic index (GI)*
- A low-protein, low-GI diet
- A high-protein (25% of energy consumed), low-GI diet
- A high-protein, high-GI diet
- A control group which followed the current dietary recommendations without special instructions regarding glycemic index levels
A high-protein, low-GI diet works best
A total of 938 overweight adults with a mean body mass index (BMI) of 34 kg/sq m were initially placed on an 800-kcal-per-day diet for eight weeks before the actual diet intervention was initiated. A total of 773 adult participants completed this initial weight-loss phase and were then randomly assigned to one of five different diet types, where 548 participants completed the six-month diet intervention (completion rate of 71%).
Fewer participants in the high-protein, low-GI groups dropped out of the project than in the low-protein, high-GI group (26.4% and 25.6%, respectively, vs. 37.4%; P = 0.02 and P = 0.01 for the two comparisons, respectively). The initial weight loss on the 800-kcal diet was an average of 11.0 kg.
The average weight regain among all participants was 0.5 kg, but among the participants who completed the study, those in the low-protein/high-GI group showed the poorest results with a significant weight gain of 1.67 kg. The weight regain was 0.93 kg less for participants on a high-protein diet than for those on a low-protein diet and 0.95 kg less in the groups on a low-GI diet compared to those on a high-GI diet.
The children's study
The results of the children's study have been published in a separate article in Pediatrics. In the families, there were 827 children who only participated in the diet intervention. Thus, they were never required to go on a diet or count calories – they simply followed the same diet as their parents. Approx. 45% of the children in these families were overweight. The results of the children's study were remarkable: In the group of children who maintained a high-protein, low-GI diet the prevalence of overweight dropped spontaneously from approx. 46% to 39% – a decrease of approx. 15%.
Proteins and low-GI foods ad libitum – the way ahead
The Diogenes study shows that the current dietary recommendations are not optimal for preventing weight gain among overweight people. A diet consisting of a slightly higher protein content and low-GI foods ad libitum appears to be easier to observe and has been documented to ensure that overweight people who have lost weight maintain their weight loss. Furthermore, the diet results in a spontaneous drop in the prevalence of overweight among their children.
Citation: Thomas Meinert Larsen, Ph.D., Stine-Mathilde Dalskov, M.Sc., Marleen van Baak, Ph.D., Susan A. Jebb, Ph.D., Angeliki Papadaki, Ph.D., Andreas F.H. Pfeiffer, M.D., J. Alfredo Martinez, Ph.D., Teodora Handjieva-Darlenska, M.D., Ph.D., Marie Kunešová, M.D., Ph.D., Mats Pihlsgård, Ph.D., Steen Stender, M.D., Ph.D., Claus Holst, Ph.D., Wim H.M. Saris, M.D., Ph.D., and Arne Astrup, M.D., Dr.Med.Sc. for the Diet, Obesity, and Genes (Diogenes) Project, 'Diets with High or Low Protein Content and Glycemic Index for Weight-Loss Maintenance', N Engl J Med 2010; 363:2102-2113 November 25, 2010
Dieters often try to avoid thinking about the foods they crave, but maybe that's the wrong approach.Imagining yourself biting into a luscious piece of chocolate cake – thinking about the way it smells, the creamy texture of frosting on your tongue – may make you eat less of it, a new study suggests. This finding challenges age-old conventional wisdom that tells us thinking about goodies increases our cravings and ultimately our consumption, according to a study from Carnegie Mellon.
Drawing on research that shows mental imagery and perception affect emotion and behavior, the research team – led by assistant professor of social and decision sciences Carey Morewedge – found that repeatedly imagining indulging in a treat decreases ones desire for it.
“These findings suggest that trying to suppress one's thoughts of desired foods in order to curb cravings for those foods is a fundamentally flawed strategy,” Morewedge said in a statement.
The researchers conducted five experiments in which 51 people were asked to imagine themselves doing a series of repetitive actions – including, in one experiment, eating different amounts of M&Ms. A control group imagined putting coins into a washing machine.
Subjects were then invited to eat their fill of M&Ms. Those who had imagined eating the most ultimately ate fewer candies than the others. Subsequent experiments confirmed the results.
The researchers say their results, which were published in the December 10 issue of Science, could have wide-ranging effects.
Says Morewedge: “We think these findings will help develop future interventions to reduce cravings for things such as unhealthy food, drugs and cigarettes, and hope they will help us learn how to help people make healthier food choices.”
Treating obese women's depression may help them lose weight, a new study suggests. Although researchers couldn't determine which condition may cause the other, obesity and depression frequently strike together. Obese women who saw their depression lessened in a treatment program also lost more weight than women whose depression didn't improve or worsened, researchers said.
“I expect that the relationship between depression and physical activity goes in both directions,” said study researcher Dr. Gregory Simon, a senior investigator and psychiatrist at Group Health Research Institute in Seattle. “Increased physical activity leads to improvement in depression, and improvement in depression leads to increased physical activity.” “You can't prove which came first.”
The researchers evaluated 203 women, ages 40 to 65, who had an average body mass index of 38.3 at the study's start, and found that obesity increased a woman's risk of depression by 50 percent to 150 percent.
Participants were then split into two groups: one focused only on helping the women lose weight, and the other also treating the women's depression. The researchers held 26 group treatment sessions over 12 months, and checked in on the women six, 12 and 24 months after the study began.
Of those whose depression had loosened its grip — as measured by a small drop on a test called the Hopkins Symptom Checklist depression score — 38 percent had lost at least 5 percent of their body weight. Of those whose depression scores stayed the same or increased, 21 percent lost that much weight.
While the study's purpose wasn't to make recommendations about exercise, Simon said, it's advisable for people suffering from depression to seek more opportunities for physical activity. “There certainly is evidence that exercise alone is an effective treatment for depression, whether you're overweight or obese or not, or even if you're a normal weight,” he said.
The study was unusual because it focused on the sometimes-overlooked link between depression and obesity, without focusing solely on the role of weight loss, said Robert E. Thayer, a psychology professor at California State University in Long Beach who has researched how people regulate their moods with food and exercise.
“These findings suggest that, like other negative moods that motivate eating as a kind of self-medication, depression is no exception,” said Thayer, who was not involved with the study. “It's a useful addition to the scientific literature.”
Simon said future studies could focus on learning which antidepressants — many of which can bring on weight gain as a side effect — contribute most to that situation. “Losing weight can certainly have a positive effect on people's moods,” he said.
The research was published in the November/December issue of the journal General Hospital Psychiatry.
The research is being presented at the conference of the British Society for Research on Ageing (BSRA) in Newcastle. It was conducted by scientists at the BBSRC Centre for Integrated Systems Biology of Ageing and Nutrition (CISBAN) at Newcastle University.
Working with the theory that cell senescence – the point at which a cell can no longer replicate – is a major cause of ageing the researchers set out to investigate what effect a restricted diet had on this process. By looking at mice fed a restricted diet the team found that they had a reduced accumulation of senescent cells in their livers and intestines. Both organs are known to accumulate large numbers of these cells as animals age.
Alongside this the CISBAN scientists also found that the telomeres of the chromosomes of the mice on restricted diets were better maintained despite their ageing. Telomeres are the protective 'ends' of chromosomes that prevent errors, and therefore diseases, occurring as DNA replicates throughout an organisms lifetime but they are known to become 'eroded' over time.
The adult mice were fed a restricted diet for a short period of time demonstrating that it may not be necessary to follow a very low calorie diet for a lifetime to gain the benefits the scientists found.
Chunfang Wang, the lead researcher on this project at CISBAN, said: “Many people will have heard of the theory that eating a very low calorie diet can help to extend lifespan and there is a lot of evidence that this is true. However, we need a better understanding of what is actually happening in an organism on a restricted diet. Our research, which looked at parts of the body that easily show biological signs of ageing, suggests that a restricted diet can help to reduce the amount of cell senescence occurring and can reduce damage to protective telomeres. In turn this prevents the accumulation of damaging tissue oxidation which would normally lead to age-related disease.”
Professor Thomas von Zglinicki, who oversaw the research, said: “It's particularly exciting that our experiments found this effect on age-related senescent cells and loss of telomeres, even when food restriction was applied to animals in later life. We don't yet know if food restriction delays ageing in humans, and maybe we wouldn't want it. But at least we now know that interventions can work if started later. This proof of principle encourages us at CISBAN in our search for interventions that might in the foreseeable future be used to combat frailty in old patients.”
CISBAN is one of the six BBSRC Centres for Integrative Systems Biology. The centres represent a more than £40M investment by the Biotechnology and Biological Sciences Research Council (BBSRC) to support the development of systems biology in the UK. The centres are also supported by the Engineering and Physical Sciences Research Council.
Systems biology uses the study of a whole, interconnected system – a cell, an organism or even an ecosystem – with computer modelling to better make the outputs of biology more useful to scientists, policymakers and industry.
Prof Douglas Kell, BBSRC Chief Executive and keynote speaker at the BSRA Conference, said: “As lifespan continues to extend in the developed world we face the challenge of increasing our 'healthspan', that is the years of our lives when we can expect to be healthy and free from serious or chronic illness. By using a systems biology approach to investigate the fundamental mechanisms that underpin the ageing process the CISBAN scientists are helping to find ways to keep more people living healthy, independent lives for longer.”