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Researchers at Children’s Hospital in Boston who studied the impact of three common diets on 21 overweight and obese adults over four years found that a low-fat diet seems to increase the risk of regaining weight. The researchers, curious about which diet is better at keeping weight off after initial weight loss, found the risk was less with a low-glycemic index diet, and least with a very low-carbohydrate diet. "These findings suggest that a strategy to reduce glycemic load rather than dietary fat may be advantageous for weight-loss maintenance and cardiovascular disease prevention,” the authors wrote.
"Effects of Dietary Composition on Energy Expenditure During Weight-Loss Maintenance", JAMA, June 27, 2012
A study of 44,000 Swedish women aged 30 to 49 who followed a high-protein, low-carb diet over 15 years found a slightly higher risk of cardiovascular disease, including heart disease and stroke. Figures adjusted for various control factors showed an additional four to five cases of cardiovascular diseases per 10,000 women a year compared with those who did not regularly eat a low carbohydrate, high protein diet. The researchers acknowledged that the differences were small, but nevertheless represented a 28 percent increase in the number of cases. They said the results are disturbing in young women who may be exposed to these dietary patterns and face the excess risk for many years.
"Low carbohydrate-high protein diet and incidence of cardiovascular diseases in Swedish women: prospective cohort study", British Medical Journal, June 27, 2012
U.S. researchers who studied 163 healthy, postmenopausal women (aged 57 to 85) taking various levels of vitamin D and calcium supplements daily for a year found that a significant number developed a condition associated with an increased risk of kidney stones. A third of the participants developed high urinary levels of calcium (hypercalciuria) at some time during the study. These participants had 88 episodes of high urinary calcium. Hypercalciuria has been linked to an increased risk of kidney stones in previous studies. However, no incidents of kidney stones were reported during the study.
"LongTerm Calcium and Vitamin D Supplement Use May Be Linked to Increased Risk of Kidney Stones", News release, presentation at The Endocrine Society annual meeting, June 27, 2012
A survey of students in 151 schools in Alberta province found that kids who participated in cooking and meal preparation at home showed a greater preference for eating fruits and vegetables over junk food. About a third of students surveyed said they helped cook meals at least once a day, and another third said they helped one to three times a week. Only 12.4 percent stayed out of the kitchen entirely. One of the researchers said the findings show the value of getting kids interested in meal preparation in the home, and suggested there could be a role for schools as well.
"Involvement in home meal preparation is associated with food preference and self-efficacy among Canadian children", Public Health Nutrition, June 27, 2012
Losing weight is an effective way for obese older people to prevent metabolic syndrome that leads to diabetes. But a weight loss program is even more beneficial when exercise is included, a U.S. study has found. Metabolic syndrome is a group of problems that raise the risk of type 2 diabetes and heart disease: symptoms include abdominal obesity, high blood pressure and high blood glucose. Researchers measured various metabolic markers for 93 study participants, finding that exercise alone did not lead to improvements. Dietary changes improved the measurements by 40 percent, while diet plus exercise improved markers by 70 percent.
"Diet Exercise or Both What Obese Older Adults Need to Do to Reduce Cardiometabolic Risk", News release, presentation at The Endocrine Society annual meeting, June 25, 2012
Israeli researchers report that adding a small “dessert” to the breakfast of a restricted calorie diet reduces hunger pangs during the day and helps dieters keep off lost pounds. For the eight-month study, 200 obese adults in two groups were limited to 1,600 calories a day. One group ate a 304-calorie breakfast with 10 grams of carbs and 30 grams of protein. The other group ate a 600-calorie breakfast with 45 grams of protein and 60 grams of carbs, including a small dessert consisting of chocolate, a doughnut, etc. Participants in both groups lost about 33 pounds on average during the first four months, but the low-carb group regained 22 pounds; the desert group lost another 15 pounds.
"Meal timing and composition influence ghrelin levels, appetite scores and weight loss maintenance in overweight and obese adults", Steroids, June 25, 2012
Scientists in Spain have determined that measuring the levels of two hormones before a dieting program is begun can accurately predict whether dieters will regain lost weight. The two hormones – leptin and ghrelin – help regulate the appetite. The researchers found the pre-diet leptin/ghrelin ratio to be two times higher among study participants who later regained weight than among those who did not. They also identified cut-off points that predicted more than 60 percent of patients who would later regain 10 percent or more of the weight they initially lost. Calculating the leptin/ghrelin ratio might help in personalizing weight-loss programs for more effective control of obesity, the researchers said.
"Ratio of Appetite Regulating Hormones Marker of Successful Dieters", News release, presentation at The Endocrine Society annual meeting, June 25, 2012
A study of more than 4,600 women aged 65 or older has found that those with low levels of vitamin D in their blood gained an average of two pounds more over five years than women whose vitamin D levels were sufficient. According to the U.S. researchers, about 80 percent of the women in the study had insufficient levels of vitamin D, a primary source of which is sunlight. The researchers said the fact that fewer people spend time outdoors in the sun could partially explain vitamin D deficiencies and chronic weight gain. They declined to recommend vitamin D supplements, however, until further studies are conducted.
"Associations Between 25-Hydroxyvitamin D and Weight Gain in Elderly Women", Journal of Women's Health, June 25, 2012
High doses of the natural antioxidant compound resveratrol improved the physical performance, heart function and muscle strength in laboratory rats, similar to the way endurance exercise improves heart and muscle performance, Canadian researchers have found. Resveratrol, found in red wine, nuts and some fruits, could be used to help patients who want to exercise but are physically incapable, the researchers said. “Our findings provide evidence that the capacity for fatty acid oxidation is augmented by the addition of resveratrol to the diet during exercise training.”
"Improvements in skeletal muscle strength and cardiac function induced by resveratrol during exercise training contribute to enhanced exercise performance in rats", The Journal of Physiology, June 22, 2012
U.S. researchers have found that overweight, but otherwise healthy, middle-aged and older adults who consumed omega-3 fatty acid supplements for four months had significantly lower levels of a protein in the blood that indicates the presence of inflammation associated with a variety of diseases and disorders. Omega-3 supplements lowered the protein level by ten percent and slightly lowered the level of another marker for inflammation. Participants in the study who consumed placebo oil capsules over four months, however, experienced average increases of 36 percent and 12 percent in those same markers.
"Omega-3 supplementation lowers inflammation in healthy middle-aged and older adults: A randomized controlled trial", Brain, Behavior, and Immunity, June 22, 2012
Spanish researchers who studied health data and physical activity patterns from 1,978 adolescents found that some dietary habits – eating more than four scheduled meals a day, or not eating too fast – were associated with lower body fat levels, with or without free-time exercise. The researchers also noted that eating breakfast every day was especially beneficial for young men who do not exercise, because those who skipped breakfast showed higher body fat values.
"Eating Habits and Total and Abdominal Fat in Spanish Adolescents: Influence of Physical Activity", Journal of Adolescent Health, June 22, 2012
U.S. researchers who analyzed the impact of 679 micoRNAs, which were once considered “junk DNA,” found that when they go haywire they can cause abnormal gene expression that leads to cancer. For their study, the researchers traced the actions of a known carcinogen in cooked meat to its effects on microRNA and cancer stem cells, finding a direct link. On the bright side, however, they also found in animal experiments that eating spinach seems to partially offset the damaging effects of the carcinogen.
"MicroRNA profiling of carcinogen-induced rat colon tumors and the influence of dietary spinach", Molecular Nutrition & Food Research, June 22, 2012
A natural substance found in apple peels known as ursolic acid not only helps increase muscle mass and strength, it also seems to reduce obesity, pre-diabetes and fatty liver disease, new U.S. research in mice has found. The scientists believe the increased muscle mass from intake of ursolic acid may explain the reduction in obesity. But they also found that ursolic acid increased brown fat, an efficient calorie burner, in mice fed a high-fat diet. Their next step is to test the effect of ursolic acid in clinical trials.
"Ursolic Acid Increases Skeletal Muscle and Brown Fat and Decreases Diet-Induced Obesity, Glucose Intolerance and Fatty Liver Disease", PLoS ONE, June 22, 2012
Scientific evidence of the dangers of fructose consumption continues to pile up, but new research takes a contrarian view that should cheer up the sugar industry. A Canadian review of 18 clinical trials involving 209 participants with either type 1 or type 2 diabetes found that fructose significantly improved blood sugar control. The improvement was similar to that achieved by an oral anti-diabetes drug. Moreover, the improvement came without adverse impact on body weight, blood pressure, uric acid (gout) or cholesterol. Participants in the trials were fed diets in which fructose was incorporated or sprinkled on foods such as cereals or coffee.
"Effect of Fructose on Glycemic Control in Diabetes: A systematic review", Diabetes Care, June 21, 2012
A U.S. study of older women – average age 59 – finds that aging does not prevent or ward off eating disorders. Among women over 50, 3.5 percent report binge eating, eight percent report purging, and more than 70 percent are trying to lose weight. Sixty-two percent of women said their weight or shape negatively affected their life. More than a quarter of the participants – 92 percent of whom were white – were obese, 29 percent were overweight, 42 percent were normal weight and two percent were underweight. The researchers urged healthcare providers to “remain alert for eating disorder symptoms and weight and shape concerns” that could harm the physical and psychological wellbeing of aging women.
"Eating disorder symptoms and weight and shape concerns in a large web-based convenience sample of women ages 50 and above", International Journal of Eating Disorders, June 21, 2012
Half of diabetics develop a disabling condition known as diabetic neuropathy, which leaves feet and legs feeling tingly, numb, painful or weak. Neuropathy can be prevented by strict control of blood sugar levels. But a U.S. and British review of six clinical studies of enhanced glucose control methods – extra insulin injections, anti-diabetic drugs, and diet changes – has found that they can be effective, there is a significant risk of adverse effects, including hypoglycemia. Further research is needed to find optimum target levels for safe treatments that will both prevent neuropathy and minimize serious side effects, according to the scientists who conducted the review.
"Enhanced glucose control for preventing and treating diabetic neuropathy", Cochrane Review, June 13, 2012
A systematic review of three British short-term clinical trials involving more than 3,500 people aged 60 or over has found that omega-3 fish oil supplements probably do not help older people retain cognitive function. The researchers acknowledged that the studies were relatively short, so the longer term effects of omega-3 fatty acids on cognitive decline and dementia need to be further explored. The trials, which were conducted for up to four years, compared the effects of omega-3 fatty acids taken in capsules or margarine to the effects of sunflower oil, olive oil or regular margarine (placebos). Participants given omega-3s did not score better in mental state examinations, or in memory and verbal fluency tests.
". Omega 3 fatty acid for the prevention of cognitive decline and dementia", The Cochrane Library, June 13, 2012
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Purdue University, June 19, 2012
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