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.
“However,” the researcher said, “there is a lack of clinical studies of the effect of vitamin D supplementation for preventing respiratory infections.”
For the current study, Laaksi's team randomly assigned 164 male military recruits to take either 400 international units (IU) of vitamin D or inactive placebo pills every day for six months — from October to March, covering the months when people's vitamin D stores typically decline and when respiratory infections typically peak.
At the end of the study, the researchers found no clear difference between the two groups in the average number of days missed from duty due to a respiratory infection — which included bronchitis, sinus infections, pneumonia, ear infections and sore throat.
On average, men who took vitamin D missed about two days from duty because of a respiratory infection, compared with three days in the placebo group. That difference was not significant in statistical terms.
However, men in the vitamin D group were more likely to have no days missed from work due to a respiratory illness.
Overall, 51 percent remained “healthy” throughout the six-month study, versus 36 percent of the placebo group, the researchers report.
The findings, Laaksi said, offer “some evidence” of a benefit from vitamin D against respiratory infections.
Still, the extent of the benefit was not clear. While recruits in the vitamin group were more likely to have no days missed from duty, they were no less likely to report having cold-like symptoms at some point during the study period.
Moreover, recent studies on the usefulness of vitamin D for warding off respiratory ills have come to conflicting conclusions.
A study of Japanese schoolchildren published earlier this year found that those given 1,200 IU of vitamin D each day during cold and flu season were less likely to contract influenza A. Of 167 children given the supplement, 18 developed the flu, compared with 31 of 167 children given placebo pills.
On the other hand, a recent study of 162 adults found that those who took 2,000 IU of vitamin D everyday for 12 weeks were no less likely to develop respiratory infections than those given placebo pills.
Laaksi said that larger clinical trials looking at different doses of vitamin D are still needed before the vitamin can be recommended for curbing the risk of respiratory infections.
In the U.S., health officials recommend that adults up to the age of 50 get 200 IU of vitamin D each day, while older adults should get 400 to 600 IU. The upper limit is currently set at 2,000 IU per day; higher intakes may raise the risks of side effects.
Symptoms of vitamin D toxicity are often vague and include nausea, vomiting, constipation, poor appetite and weight loss. Excessive vitamin D in the blood can also raise blood pressure or trigger heart rhythm abnormalities.
Some researchers believe that people need more vitamin D than is currently recommended, and that intakes above 2,000 IU per day are safe. However, exactly what the optimal vitamin D intake might be remains under debate.
Food sources of vitamin D include milk, breakfast cereals and orange juice fortified with vitamin D, as well as some fatty fish, like salmon and mackerel. Experts generally recommend vitamin pills for people who do not get enough of the vitamin from food.
SOURCE: Journal of Infectious Diseases
The randomized, double-blind, placebo-controlled study, which was funded by The Dannon Company, Inc., involved 638 healthy children aged three to six, all of whom attended school five days a week. Parents were asked to give their child a strawberry yogurt-like drink every day. Some of the drinks contained the probiotic strain Lactobacillus casei (L. casei) and the others did not. Parents were also asked to record how many yogurt drinks their child consumed and to keep notes on their child's health.
At the end of the study, there was a 19 percent decrease in the number of common infections—e.g., ear infections, flu, diarrhea, sinusitis–among children who had consumed the yogurt drink with the probiotics than those who had the drink without the beneficial bacteria. When the researchers broke out the individual types of illness, they found that children who had the probiotic beverage had 24 percent fewer gastrointestinal infections (e.g., diarrhea, nausea, vomiting), and 18 percent fewer upper respiratory tract infections (e.g., ear, sinusitis, strep).
The reduction in infections did not, however, result in fewer days lost from school. Merenstein commented that “It is my hope that safe and tolerable ways to reduce illnesses could eventually result in fewer missed school days which means fewer work days missed by parents.”
The finding that the probiotic yogurt drink reduced infections in children, however, is significant. This joins results from other studies demonstrating benefits of probiotics in children, including one published in Pediatrics in which they reduced cold and flu symptoms, another in which they eased diarrhea, and one showing they helped prevent eczema in infants. Generally, probiotics have also been shown to benefit people who have celiac disease, irritable bowel, colitis, and possibly autism.
Georgetown University Medical Center