Higher intakes of the B vitamins thiamine and riboflavin from the diet may reduce the incidence of premenstrual syndrome (PMS) by about 35 percent, suggest new findings. According to a new paper published in the American Journal of Clinical Nutrition, the link between B vitamins and PMS is biologically plausible since B vitamins such as thiamine and riboflavin are known to play important roles in the synthesis of various neurotransmitters involved in PMS.
While most women experience mild emotional or physical premenstrual symptoms, as many as 8-20 per cent of women experience symptoms severe enough to meet the definition of premenstrual syndrome, which can substantially interfere with daily activities and relationships. The new study, performed by researchers from the University of Massachusetts, Harvard, and the University of Iowa, indicates that increase intakes of certain B vitamins from food sources may help reduce the incidence of PMS.
Using data from 1,057 women with PMS and 1,968 women without PMS participating in the Nurses' Health Study II cohort, the researchers found that women with the highest average intakes of riboflavin two to four years prior to diagnosis were associated with a 35 percent lower incidence of PMS than women with the lowest average intakes. On the other hand, the researchers did not observe any benefits with other B vitamins, including niacin, folate, B6, and B12. In addition, supplemental intakes of these vitamins was not linked to PMS incidence, they added. “We observed a significantly lower risk of PMS in women with high intakes of thiamine and riboflavin from food sources only,” wrote the researchers. “Further research is needed to evaluate the effects of B vitamins in the development of premenstrual syndrome.”
Beyond the B vitamins, there is also some evidence for the potential of a diet rich in calcium and vitamin D to lower the risk of developing PMS, a condition that affects up to a fifth of all women. According to a study published in 2005 in the Archives of Internal Medicine (Vol. 165, pp1246-1252), researchers from the University of Massachusetts and GlaxoSmithKline reported for the first time that calcium and vitamin D may help prevent the initial development of PMS.
Source: The American Journal of Clinical Nutrition. Published online ahead of print, doi: 10.3945/ajcn.110.009530 “Dietary B vitamin intake and incident premenstrual syndrome” Authors: P.O. Chocano-Bedoya, J.E. Manson, S.E. Hankinson, W.C. Willett, S.R. Johnson, L. Chasan-Taber, A.G. Ronnenberg, C. Bigelow, E.R. Bertone-Johnson
Drinking soft drinks is associated with higher blood pressure, according to a study of over 2,500 people reported this week in the journal Hypertension. High blood pressure is a major risk factor for heart disease, which is the leading cause of death worldwide. Someone with a blood pressure level in millimetres of mercury (mmHg) of 135 over 85 is twice as likely to have a heart attack or stroke as someone with a reading of 115 over 75.
The new research shows that for every extra can of soft drink consumed per day, participants on average had a higher systolic blood pressure by 1.6 mmHg and a higher diastolic blood pressure by 0.8 mmHg. This difference was statistically significant even after adjusting for factors such as weight and height. The study did not examine the mechanism that might link soft drinks with blood pressure. However, the researchers suggest that raised uric acid, which has been linked to soft drink consumption, might raise blood pressure by reducing the levels of nitric oxide, a chemical that relaxes the lining of the blood vessels.
The association between soft drinks and higher blood pressure was especially strong in people who consumed a lot of salt as well as sugar. Diet drinks were linked with lower blood pressure levels in some analyses, but the association was not consistent or strong. Professor Paul Elliott, senior author of the study, from the School of Public Health at Imperial College London, said: “It’s widely known that if you have too much salt in your diet, you’re more likely to develop high blood pressure. The results of this study suggest that people should be careful about how much sugar they consume as well.”
The researchers analysed data from 2,696 volunteers aged between 40 and 59, in eight areas of the US and two areas of the UK. On four separate occasions over a period of three weeks on average, the participants reported what they had eaten in the preceding 24 hours, as well as giving urine samples and having their blood pressure measured. The volunteers were taking part in INTERMAP, the International Study of Macronutrients, Micronutrients and Blood Pressure.
The researchers also found that people who drink more soft drinks tended to have more unhealthy diets in general. As well as consuming more sugar, those consuming more than one soft drink a day consumed more calories by 397 kilocalories per day on average, and less fibre and minerals. Those who did not consume soft drinks had a lower body mass index (BMI) on average than those who consumed more than one drink per day. “Individuals who drink a lot of sugar-sweetened beverages appear to have less healthy diets,” said Dr Ian Brown, the study’s first author, also from the School of Public Health at Imperial College London. “They are consuming empty calories without the nutritional benefits of real food. They consume less potassium, magnesium and calcium.” “This is a population study,” Dr Brown added. “It can’t say definitively that sugary drinks raise your blood pressure, but it’s one piece of the evidence in a jigsaw puzzle that needs to be completed. In the meantime, we would advise people who want to drink sugar-sweetened beverages should do so only in moderation.”
Excessive intake of sugar-sweetened beverages like soft drinks and fruit juices that offer no nutritional value other than calories to the diet of teenagers can elevate their risk of heart disease in later life, claims a new study. According to health experts, there is growing evidence of the link between excess sugar consumption among youngsters and a number of health conditions such as obesity, hypertension, elevated triglycerides that are considered markers for heart disease. Lead author of the study, Jean Welsh, post-doctoral fellow at Emory University School of Medicine in Atlanta stated, “We need to be aware of sugar consumption. “It’s a significant contributor of calories to our diet and there are these associations that may prove to be very negative. “Sugar-sweetened soft drinks and sodas are the major contributor of added sugar and are a major source of calories without other important nutrients. “Parents and adolescents need to become aware of the amount of added sugar they are consuming and be aware that there may be some negative health implications if not now, then down the line.”
According to the American Heart Association (AHA) recommendations, a teenager who requires 2,200 calories may have an upper limit of 150 calories from added sugar while someone with an energy requirement of 1,800 calories per day should limit added sugar to 100 calories. However, the National Health and Nutrition Survey (NHANES) of 2,157 teenagers aged 12 to 18 years found that the average teenager consumes close to 500 calories added sugars each day. “Adolescents are eating 20 per cent of their daily calories in sugars that provide few if any other nutrients,” said Jean Welsh.
In order to get an insight into the impact of high sugar consumption in adolescence on the risk of cardiovascular disease in later life the researchers studied 646 teenagers. For the purpose of the study, they analyzed the 24-hour dietary recall by teens with data from the US Department of Agriculture on sugar content in foods. It was noted that the teens’ average daily consumption of added sugars was three to five times higher that the limit acceptable by the AHA.
The study found, that teens who consumed 30 percent or more of total calories from added sugars exhibited lower levels of HDL, or “good” cholesterol and higher levels of triglycerides and LDL or “bad” cholesterol, compared to those who ate less than 10 percent of added sugar. In addition, it was observed that obese and overweight teenagers who consumed more sugar also had the most insulin resistance.
Although the study hints at a possible association between added sugar intake and poor cholesterol profiles as well as other heart disease risk factors, researchers feel there is need for more research to substantiate the findings. Welsh stated, “We need controlled studies to really understand the role of added sugars in cardiovascular disease. But it is important to be aware of the added sugar in the foods we all eat.”
The study is published in the American Heart Association (AHA) journal ‘Circulation.’
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 shows following a Mediterranean style diet rich in vegetables, olive oil, and fish may keep the mind sharp and slow age-related cognitive decline.The diet typified by the Italians, Greeks, and other Mediterranean cultures has already been shown to reduce the risk of heart disease, diabetes, and some types of cancer. But this and other studies are now suggesting that the diet may also have healthy benefits for the mind.
The Mediterranean diet emphasizes fruits and vegetables, fish, legumes, non-refined cereals, olive oil, and moderate wine consumption, usually at meals. Researchers found older adults who followed the diet more closely had slower rates of age-related cognitive decline than those who didn't, even after adjusting for other factors such as educational level. “The more we can incorporate vegetables, olive oil, and fish into our diets and moderate wine consumption, the better for our aging brains and bodies,” says Christy Tangney, PhD, associate professor of clinical nutrition at Rush University, in a news release.
In the study, published in the American Journal of Clinical Nutrition, researchers analyzed information gathered by the ongoing Chicago Health and Aging Project, which follows 3,759 adults over the age of 65 living on the South Side of Chicago. Every three years, the participants took tests of memory and basic math skills and filled out a questionnaire on how often they eat 139 different foods. The study follow-up time was 7.6 years on average.
Researchers looked at how closely the participants followed a Mediterranean diet and then compared it to their scores on age-related cognitive decline. Out of a maximum score of 55 for total adherence to a Mediterranean diet, the average score was 28. The results showed those with higher than average scores had a slower rate of age-related mental decline than those with lower scores. Researchers also looked at how closely the participants followed the Healthy Eating Index-2005, which is based on the 2005 Dietary Guidelines for Americans. They found no relationship between adherence to this type of diet and the rate of age-related cognitive decline.
The steep rate of death from stroke in a swath of Southern states often referred to as America's “stroke belt” may be linked to a higher consumption of fried fish in that region, new research suggests. A study published in the journal Neurology shows people living in the stroke belt — which comprises North Carolina, South Carolina, Georgia, Alabama, Mississippi, Tennessee, Arkansas and Louisiana — eat more fried fish and less non-fried fish than people living in the rest of the country, and African-Americans eat more fried fish than Caucasians. “Differences in dietary fish consumption, specifically in cooking methods, may be contributing to higher rates of stroke in the stroke belt and also among African Americans,” says study author Fadi Nahab, medical director for the Stroke Program at Emory University Hospital in Atlanta.
The research, part of a large government-funded study, Reasons for Geographic and Racial Differences in Stroke (REGARDS), involved 21,675 participants from across the country; the average age was 65. Of the participants, 21% were from the “stroke buckle,” the coastal plain region of North Carolina, South Carolina and Georgia where stroke mortality rates are even higher than they are in the rest of the stroke belt. Another 34% were from the rest of the stroke belt and 44% were from the other states.
Participants were interviewed by phone and then given an in-home physical exam. The questionnaire asked how often they ate oysters, shellfish, tuna, fried fish and non-fried fish. The American Heart Association recommends people eat fish high in omega-3 fatty acids—essential fatty acids humans get through their diet—at least twice a week, baked or grilled but not fried. Fewer than one in four overall ate two or more servings of non-fried fish a week. Stroke belt residents were 32% more likely to eat two or more servings of fried fish each week than those in the rest of the country.
African-Americans were more than 3.5 times more likely to eat two or more servings of fried fish each week than Caucasians, with an overall average of about one serving per week of fried fish compared with about half a serving for Caucasians. When it came to eating non-fried fish meals, stroke belt residents ate an average of 1.45 servings per week, compared with 1.63 servings eaten by people elsewhere.
“This is good stuff. It's a well-done study, but I think one thing to bear in mind is that it's not specifically a study of stroke risk. You're looking at a community and seeing how it's behaving on the whole,” says Daniel Labovitz, a stroke neurologist at Montefiore Medical Center in the Bronx. “This study can't tell you causation. It can't tell you there's a direct link between one thing and another, it just tells you they're associated,” says stroke neurologist Victor Urrutia, an assistant professor at Johns Hopkins University School of Medicine.
How might eating fried fish impact stroke?
It could be that frying the fish leaches out the omega-3s, says Jeremy Lanford, stroke director at Scott & White Healthcare in Roundrock, Texas. Or the increased fat calorie content from the frying oil may contribute to stroke, says author Nahab. He also notes that fish used for frying, such as cod and haddock, tend to be the types lower in healthy fats. More research is needed to tease out whether cooking methods affect stroke risk, Labovitz says. “In other words, is fried fish a problem, or is it another red herring?” he says.
The study was supported by the National Institute of Neurological Disorders and Stroke, the National Institutes of Health, and the Department of Health and Human Services. Funding was provided by General Mills for coding of the food frequency questionnaire.
What did the research involve?
The researchers needed to obtain several sets of data to fill their model. Data for UK deaths from coronary heart disease, stroke and cancer were obtained from the Office for National Statistics, the General Register Office for Scotland and the Northern Ireland Statistics and Research Agency. Information on the population's intake of foods and nutrients was obtained from two sources: the average intake of fatty acids, fibre, and fruit and vegetables for 2005–7 was derived from the Expenditure and Food Survey, while estimates of salt intake came from the National Diet and Nutrition Survey, 2006.
The modelling also incorporated several meta-analyses of individual studies looking at diet and disease risk factors. The researchers looked at reviews that had pooled data from randomised trials, cohort studies or case-control studies, giving priority to meta-analyses of randomised trials. These different studies were combined in the model to calculate the change in risk of disease for an individual who changes his or her diet. To estimate the change in health outcomes with a change in diet at a population level, the model used the difference between current average consumption levels and recommended levels of different foods in the UK.
What were the basic results?
In a general summary of the main findings, the researchers calculated that:
About 33,000 deaths a year would be avoided if UK dietary recommendations were met. There would be a reduction in deaths from coronary heart disease of 20,800 (95% credible interval 17,845 to 24,069), a reduction of 5,876 for deaths from stroke (3,856 to 7,364) and a reduction of 6,481 for deaths from cancer (4,487 to 8,353). About 12,500 of these avoided deaths would be in people aged 75 or under. About 18,000 of the avoided deaths would be men and 15,000 would be women. More than 15,000 of the avoided deaths (nearly half the total figure) would be due to increased consumption of fruit and vegetables. Reducing average salt intake to 6g a day would avoid 7,500 deaths annually. The greatest number of deaths avoided would be in Northern Ireland and Scotland, whose populations are furthest from achieving dietary recommendations.
How did the researchers interpret the results?
The researchers say their study suggests that increasing average consumption of fruits and vegetables to five portions a day is the target likely to offer most benefit in terms of deaths avoided. They also say that reducing recommended salt levels to 3g daily and saturated fat to 3% of total energy would achieve a similar reduction in mortality.
They conclude that their calculations based on the Dietron model are robust, pointing out that their estimate of deaths avoided is lower than a previous government survey which calculated that 70,000 deaths a year could be avoided if government dietary recommendations were met. The estimates could be used in calculating the allocation of resources for interventions aimed at reducing chronic disease.
This well-conducted modelling study used various data sources to link consumption of different dietary components with disease risk factors (for example blood pressure, cholesterol and obesity) and subsequent mortality from coronary heart disease, stroke and cancer. The study supports previous research showing that diet plays a crucial role in health and that a diet with plenty of fruit and vegetables, fibre and low fat and salt levels can reduce the risk of chronic disease, in particular coronary heart disease. However, its predictions are made at the population level. A model such as this cannot predict individual risk, which will depend on many factors, including family history, smoking and other lifestyle habits.
It is important to note that the figures are based on the estimates and assumptions made when using a mathematical model, and not on reality. As the authors themselves note, the modelling technique they used may have led to “some degree of double counting” and that, therefore, their estimate of reduced mortalities if dietary recommendations were met is likely to be an overestimate. Also, the accuracy of the model depends to some extent on the quality of the meta-analyses that were included, and the quality of the individual studies that were pooled within these reviews in order to establish associations between diet and particular disease risk factors.
Overall, this study supports current dietary recommendations and even though it cannot predict how diet influences risk for individuals, it does indicate that keeping to dietary recommendations reduces the risk of disease.
Dietary recommendations include eating five portions of fruit and vegetables a day (about 440g) and 18g of fibre (provided by wholegrain foods and some fruit and vegetables). It is recommended that salt intake is limited to a maximum of 6g a day and that a third of total energy is provided by fats, with saturated fat comprising 10%. The researchers point out that in 2007, according to the estimated average intakes in the sources they used, none of the UK countries met these recommendations.
Even young children appear to be consuming more caffeine, so much so that caffeine could be contributing to sleep problems in primary school children, researchers found. Three-quarters of children ages 5 to 12 consumed caffeine on an average day in a survey of parents at routine clinic visits by William J. Warzak, PhD, of the University of Nebraska Medical Center in Omaha, and colleagues. The more caffeine children consumed, the fewer hours they slept on average (P=0.02), the researchers reported online in the Journal of Pediatrics, although not drawing a causal link. The average intake was two or three times higher than the 22- to 23-mg daily average reported nearly a decade ago, they noted.
Eight- to 12-year-olds in Warzak's study averaged 109 mg of caffeine — the equivalent of nearly three 12-oz cans of soda each day. But even the 52 mg of caffeine consumed by 5- to 7-year-olds on an typical day was well above the level known to have a physiologic effect on adults, the researchers noted. “There's really no role for caffeine in kids,” Marcie Schneider, MD, of the Albert Einstein College of Medicine in New York City, emphasized in commenting on the study. “We know that caffeine raises your blood pressure, raises your heart rate, and can be addictive.” Unlike older teens who are likely drinking coffee to wake up in the mornings for school, the assumption is that younger kids are getting most of their caffeine from soda, noted Schneider, who serves as a member of the American Academy of Pediatrics Committee on Nutrition.
She urged pediatricians to raise parents' awareness of the issue, perhaps as part of the yearly checkup. “We routinely ask kids what they're eating and drinking,” “It may be something that is worth pediatricians pointing out to parents that this kid does not need caffeine in their life partially because it does some things that are negative.”
Warzak's group surveyed parents of 228 children seen at an urban outpatient pediatric clinic during routine visits about the children's average daily consumption of drinks and snacks with an emphasis on caffeine-containing items. None of the children had a known sleep disorder or medical condition that might cause bedwetting. Illustrated depictions were provided to help parents accurately estimate serving sizes.
Nearly all of the caffeine intake was consumed through beverages. Few children got a meaningful amount of caffeine from food. “Caffeine's diuretic properties have encouraged behavioral health practitioners to eliminate caffeine from the diet of children with enuresis,” the researchers noted. However, they found that intake didn't correlate with the number of nights a child wet the bed (P=0.49). Overall, enuresis was actually less likely in children who consumed caffeine.
The researchers cautioned that interpretation of these results may be complicated by cultural differences in reporting children's behavioral health concerns and that their study could not draw any causal conclusions. Schneider also noted the use of parental reports and the relatively small sample as limitations. Although the findings offered no support for removing caffeine from children's diets on the basis of bedwetting, Warzak's group concluded in the paper that “given the potential effects of caffeine on childhood behavior, a screen of caffeine consumption might be beneficial when evaluating childhood behavioral health concerns.”
Source: Warzak WJ, et al “Caffeine consumption in young children” J Pediatr 2011; DOI: 10.1016/j.jpeds.2010.11.022.
The more obese a person is, the poorer his or her vitamin D status, a new study by a team of Norwegian researchers suggests. The study found an inverse relationship between excess pounds and an insufficient amount of vitamin D, which is critical to cell health, calcium absorption and proper immune function. Vitamin D deficiency can raise the risk for bone deterioration and certain types of cancer. The researchers also suggest that overweight and obese people may have problems processing the vitamin properly.
The team noted that after the so-called “sunshine vitamin” is initially absorbed (through either sun exposure or the consumption of such foods as oily fish and fortified milk), the body must then convert it into a usable form, called 1,25-dihydroxyvitamin D. This conversion process, however, seems to be short-circuited among obese people, complicating efforts to gauge their true vitamin D health.
The findings are published in the January issue of the Journal of Nutrition.
To investigate the impact of obesity on vitamin D absorption, the team spent six years tracking 1,464 women and 315 men, with an average age of 49. Based on the participants' body mass index (BMI), an indicator of body fatness calculated from a persons weight and height, the average participant was deemed to be obese. About 11 percent were categorized as “morbidly obese.”
From the outset, overall vitamin D levels were found to be below the healthy range, the authors noted. By the end of the study, overall levels of vitamin D were found to have dropped off “significantly” while BMI readings rose by 5 percent. The research team concluded that having a higher-than-normal weight, body fat and BMI was linked to a poorer vitamin D profile. For example, people with the lowest BMI readings had 14 percent higher vitamin D levels than those with the highest BMI readings. Because vitamin D levels did not correlate properly with 1,25-dihydroxyvitamin D levels (and in fact appeared to have an abnormal inverse relationship), the authors suggested that future efforts to explore vitamin D status among obese people should test for both measures of vitamin D health.
They also suggested that people who are overweight and obese might benefit from vitamin D supplementation and more exposure to sunlight.
SOURCE: Journal of Nutrition, news release, Dec. 14, 2010
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