A Spanish study in rats shows that high-protein diets, like Dukan and Atkins, boost the risk of developing kidney problems, unless supplemented with fruits and vegetables. Animals on a high-protein diet lost as much as 10 percent of their body weight over the 12-week study, but the protein had a negative effect on kidney structure, a signal of an increased risk of kidney disease and serious pathologies like calcium kidney stones. High protein foods drastically reduce urinary citrate, an inhibitor of calcium salt crystallization and urinary pH. The researchers noted, however, that fruits and vegetables added to the diet reduce the risk of kidney stones forming. Why? Potassium and magnesium compensate for the acidity of the high-protein diet.

People with impulsive personalities are more likely to report higher levels of food addiction and obesity, a U.S. study has found. Food addiction, a relatively new disorder, is a compulsive pattern of eating similar to drug addiction. The study used two different scales to determine levels of food addiction and impulsivity among the 233 participants, then compared these results with body mass index, a measure of obesity. Researchers said impulsive behavior was not necessarily associated with obesity, but impulsive behaviors can lead to food addiction, which is an indicator of obesity.

The Scandinavian fruit lingonberries prevented weight gain in mice that ate a high-fat diet, a Swedish study reports. The berries also reduced blood sugar and cholesterol levels. Lingonberries were tested against other berries: bilberry, raspberry, crowberry, blackberry, prune, blackcurrant or açai berry in mice fed high-fat and low-fat diets. After three months, the lingonberry group had not put on more weight than the low-fat mice, their blood sugar and insulin readings were similar, and cholesterol levels and levels of fat in the liver were lower. Blackcurrants and bilberries also produced good effects, though not as pronounced as the lingonberries, researchers said.

A proprietary algal culture – known as “PAZ” or “ProAlgaZyme” – was found to support healthy cholesterol balance by increasing “good” cholesterol (HDL) and reducing non-HDL cholesterol while consuming a high-fat diet. The testing in lab animals showed that PAZ helped remove excess cholesterol from cell storage and transported it to the liver for excretion from the body. Health Enhancement Products, Inc., maker of the algal culture extracts, says  the effects of its product in improving "good" cholesterol, and therefore cardiovascular health, “are significant and potentially wide-reaching”.

Poor methodology used in large clinical studies probing the value of vitamin supplements has rendered them mostly useless, according to U.S. scientists. Whether the studies defend or disparage the use of multivitamin and other micronutrient supplements, flaws in study design torpedo their value. Many studies have tried to analyze nutrients that are naturally available in the human diet the same way they would a powerful prescription drug, leading  to conclusions that have little scientific meaning, even less accuracy and often defy a wealth of other evidence, said one researcher. What is needed are new methodologies that accurately measure baseline nutrient levels, provide supplements or dietary changes only to participants who clearly are inadequate or deficient, and then study the resulting changes in their health.

Three companies that claimed – fraudulently – that their weight loss products helped people trim pounds effortlessly have agreed to a $34 million settlement with the Federal Trade Commission. The largest settlement – $26.5 million – was against Sensa Productions LLC, which advertised that its Sensa supplement sprinkled on food would spur weight loss. One of their bogus ads said Sensa would "help you lose 30 lbs. without dieting or spending all your time working out”. A $450,000 settlement was reached with L’Occitane, which promised that its Almond Beautiful Shape cream could “trim 1.3 inches in just 4 weeks” and that it was a “cellulite fighter”. The FTC is setting up a process for distributing the settlement money to consumers who purchased the products.

Researchers who looked for metabolic reasons why African-American women don’t lose as much weight as white women when they diet or exercise have found that the African-American women had lower resting metabolic rates and generally expended less energy during activity. That means that to lose weight they need to eat fewer – and burn more – calories than Caucasian women. The U.S. study was conducted among 39 severely obese African-American and 66 Caucasian women who participated in a six-month weight loss program. The African-American women lost about seven pounds fewer than the Caucasian women, even though their starting body mass index, or BMI, measures were comparable and they consumed the same number of calories and exercised the same way.

U.S. researchers who conducted a longitudinal cross-over study examining the effects of diet on 70 postmenopausal women found that a tomato-rich diet may help protect against breast cancer. A diet rich in tomatoes had a larger impact on the levels of hormones that regulate fat and sugar metabolism in women who maintained a healthy weight, the researchers said. Breast cancer risk rises in postmenopausal women as their body mass index climbs. With the tomato-rich diet, participants' levels of the hormone adiponectin climbed nine percent.

Dietary supplements may help some people with special nutrient needs, but generally eating a variety of nutrient-rich foods is the best way to get healthy nutrients needed to reduce the risk of chronic disease, U.S. studies have found. The studies, along with an accompanying editorial, say there really is not clear benefit for most healthy people to take vitamin supplements. Choosing foods that provide the most nutrients per calorie “can build a healthier life and start down a path of health and wellness”. Recommendations include a healthy breakfast, whole grains, fresh or frozen fruits and vegetables, omega 3-rich seafood and fiber- and folate-rich beans.

A British study involving 26 healthy, active young men who were asked to do “a lot of sitting and gorging themselves” for seven days found that those who stopped exercising completely experienced a significant, unhealthy decline in blood sugar control. In addition, their fat cells began over-expressing certain genes associated with unhealthy metabolic changes while under-expressing genes linked to a healthy metabolism. Participants who continued to exercise daily – even though they upped their calorie intake – were not affected the same way. Blood sugar control and fat cell gene expression remained normal, compared to the sedentary men.

Swedish research finds that omega-3 fatty acids in dietary supplements can cross the blood-brain barrier in people with Alzheimer's disease, affecting known markers for both the disease itself and inflammation. Earlier studies found evidence that omega-3 fatty acids protect the brain from Alzheimer’s, but the new findings strengthen the argument that omega-3s may benefit patients with certain forms of the seriously debilitating disease. Thirty-three patients participated in the study: 18 received a daily supplement; 15 received a placebo for six months. The results show that the omega-3 group – but not the placebo group – had higher levels of both DHA and eicosapentaenoic acid (EPA, another omega-3 fatty acid) in their cerebrospinal fluid and blood.

People who have tried intermittent food restriction – not quite strict feasting and then fasting – have found some health benefits in the practice, though most evidence so far is anecdotal. Intermittent restriction involves eating between 500 and 650 calories a day, every other day. On alternate days eating is normal. One 41-year-old man who has tried it for about a year – after a month-long “angry, grumpy” adjustment period – has lost 50 pounds, stopped taking medication for diabetes and no longer has stomach ulcers. A British study among three groups of overweight breast cancer patients found that two intermittent restriction groups lost twice as much weight as the daily calorie restriction group.

A low-fat – less than 15 percent – diet combined with regular intake of fish oil supplements (five grams a day) lowered the levels of inflammation-causing substances in the blood of prostate cancer patients. The diet also lowered the cell cycle progression score, a measure used to predict the recurrence of the disease. The study is follows up earlier research that found a low-fat diet with fish oil supplements eaten for four to six weeks prior to prostate removal slowed the growth of cancer cells in human prostate cancer tissue compared to a traditional, high-fat Western diet.

Pres. Obama’s Affordable Care Act mandated that restaurant chains with more than 20 locations nationwide post the calorie content of all regular food and drink items on their menus. The idea, of course, was to encourage healthier food choices. Is the strategy working? Not according to a study by New York University researchers. Posting calorie content does not change purchasing habits or decrease the number of calories customers consume, especially among lower-income and less-educated consumers. The researchers said “more robust interventional policies” should be considered in neighborhoods where obesity is most prevalent.

The market for ready-to-drink protein-fortified meals is booming, according to beverage industry observers. Mintel reported recently that 74 beverages containing protein were released in the first six months of 2013, compared to only 49 during the same period of 2012. A Wisconsin company that supplies protein ingredients to the beverage industry says America has become an “on-the-go” society that demands nutritious food – including protein – in a quick, convenient format. Consumers are also looking for “wholesome and natural” ways to consume a balanced diet. The basic trend? Beverages are no longer around just to wash down a meal – they’ve become the meal.

Researchers who published a study on the content of vegetable oils urge the Canadian government to rethink its advice on the health benefits of corn oil and safflower oil. The two commonly used oils have been on a list of oils recommended because of purported cholesterol-lowering effects. But the researchers found that the two oils contain high levels of omega-6 linoleic acid, but almost no heart-healthy omega-3 α-linoleic acids. Labels on corn oil and sunflower oil products are allowed the claim: “a reduced risk of heart disease by lowering blood cholesterol levels”. That claim is not warranted in the case of omega-6 linoleic acids, the researchers argue.

U.S. researchers who analyzed the recipe recommendations of several popular food blogs found that many of the recipes were acceptable in calories, but excessive in saturated fat and sodium. The researchers noted that the meal photos on the six blogs were probably more attractive than the actual nutritional content of the foods. Another downside is that food companies sponsor the sites, so the recipes are actually advertisements for company products. “The public should be aware of the nutritional limitations of popular food blogs,” the researchers concluded. They recommended that dietitians help bloggers modify blog recipes and partner with bloggers “to improve the nutritional profile of recipes”.

Dieters who have successfully lost weight can prevent the return of unwanted pounds by using anti-obesity drugs, meal replacements or a high-protein diet, according to new Swedish research. Scientists combined the data from 20 clinical studies involving more than 3,000 participants, who were either obese or overweight prior to dieting. The studies analyzed the impact of drugs, meal replacements, high protein diets, dietary supplements and exercise on rebound weight gain after completing low-calorie diets (less than 1,000 calories a day). Researchers found that anti-obesity drugs were effective but risky. In fact, the most effective drugs were are no longer on the market. However, “Meal replacement products and high protein diets are effective and available to everyone," they concluded.

To combat osteoporosis, patients should maintain an adequate intake of calcium, but the source of the important mineral is essential to its effectiveness, In fact, say researchers at the University of California San Francisco who reviewed earlier studies, patients and health care practitioners should focus on getting calcium from the diet – e.g., food products fortified with calcium, plus kale, broccoli and bok choy – rather than from supplements. The researchers noted, however, that if patients cannot get adequate calcium from the diet, supplements are safe and not associated with cardiovascular problems, despite recent reports to the contrary.

U.S. researchers have reported on four cases of severe liver problems that occurred after consumption of weight loss supplements, an energy drink and an energy drink. In one case, a woman who had fasted for three weeks, then ingested SlimQuick for two days, suffered liver failure and underwent a liver transplant. Other case studies involved: a woman who entered the early stages of cirrhosis after taking black cohosh to ease menstrual symptoms; a man who developed liver failure after consuming three Rockstar Sugar Free energy drinks; and a woman who suffered liver injury after three weeks of drinking Ripped Fuel, an advanced weight loss supplement. Diagnosis of liver problems is difficult when weight loss supplements are involved because patients often fail to inform their physicians.

A Canadian study has found that people with abdominal obesity – and an increased risk of heart disease, stroke, high blood pressure, diabetes and high blood cholesterol – can reduce that risk by participating in high-intensity interval training coupled with nutritional counseling on the Mediterranean diet. Researchers reported an average reduction in waist circumference of eight centimeters, a reduction in systolic blood pressure of 6 mm Hg and an aerobic fitness improvement of 15 percent over the first nine months of the study. On average, blood sugar levels improved by 23 percent in diabetic participants; the improvement was about 10 percent in individuals with pre-diabetes.

A study using DNA barcoding to analyze the plant species found in samples of herbal supplements found that 59 percent were contaminated with plant species not listed on product labels. Worse, more than two thirds of the products tested contained plant species that were substituted for the plants listed on label. A third of the products also contained other species that may be filler or simply contamination. The U.S. study also found in some products plant species that were toxic, had side effects or had negative interactions with other herbs, supplements, or medications. The researchers suggested that the herbal industry use molecular diagnostic tools such as DNA barcoding to authenticate herbal products by testing of raw materials.

U.S. researchers have found that the measurement protocols used in the National Health and Nutrition Examination Survey (NHANES) have significant limitations, rendering the nutrition data collected via the survey flawed and “implausible”. The NHANES survey, conducted by the CDC and USDA, combines interviews of self-reported food and beverage consumption over 24 hours and physical examinations to assess the health and nutritional status of the U.S. population. The researchers said data collected in the survey from 1971 through 2009 are not “physiologically credible”, because the "calories in" and the "calories out" reported by the 63,000 adult men and women don't add up. In fact, it would be impossible to survive on most of the reported energy intakes. ”It is time to stop spending tens of millions of health research dollars collecting invalid data and find more accurate measures," the researchers concluded.

Italian and U.S. scientists have for the first time used a nutritional biomarker – not just questionnaire data –  to prove that consumption of polyphenols – basically a diet rich in fruits and vegetables – increases lifespan. Polyphenols are compounds found in fruits, vegetables, coffee, tea, nuts, legumes and cereals. They have antioxidant, anti-inflammatory and anti-carcinogenic properties. The 12-year study followed 807 men and women aged 65 and over, measuring a biomarker known as total urinary polyphenol (TUP) concentration. Results showed that a high TUP – more than 650 mg of polyphenols a day – was associated with a 30 percent reduction in mortality.

A small American clinical study among adults with a higher-than-healthy body mass index (BMI) finds that consuming walnuts can improve blood vessel dilation and reduce the risk of diabetes and heart disease. Participants had a BMI larger than 25, and a waist circumference exceeding 40 inches for men and 35 inches for women. All had one or more risk factors for metabolic syndrome, a precursor of diabetes and cardiovascular disease. The group was randomly assigned to two 8-week sequences, eating either a walnut-enriched – 56 grams a day – regular diet or a regular diet without walnuts. Those on the walnut-enhanced diet showed improved blood flow in the brachial arterly and lower systolic blood pressure. And eating the walnuts did not lead to weight gain.

The brain likes sweets, and is not fooled by the artificial varieties, according to new U.S. research. The study in mice discovered a physiological brain signal critical for determining choice between sugars and sweeteners. The signal regulates dopamine levels, the chemical necessary for reward signaling in the brain, and is activated only when sugar is broken down into a form usable as fuel for cells to function. In other words, greater reward in the brain is attributed to sugars than to artificial sweeteners. To sidestep the obesity problem associated with sugar intake, the researchers suggest combining sweeteners with minimal amounts of sugar. That way energy metabolism doesn't drop, and caloric intake is minimized.

A Yale University study involving 190 people – 26 percent of whom were men – who had sought treatment for obesity and binge eating disorder found that men are much more likely to suffer serious health consequences than women. Binge eating disorder involves repeatedly eating large amounts of food in a short time without any compensating activity, like the vomiting associated with bulimia. After adjusting for race and body mass index, men in the study were three times more likely than the women to meet the criteria for metabolic syndrome, a condition that increases the risk of cardiovascular disease.

Commercial baby foods in the U.K. that are promoted as a way to wean children from breast milk are actually sweet foods that provide little extra nutritional benefit over breast milk or formula,  according to new research. British government guidelines say infants should not be weaned before six months, and the foods they eat – cereals, vegetables, fruits and proteins – should be introduced gradually. The researchers looked at products from four manufacturers, finding that commonly used commercial foods supplied no more energy than breast or formula milk and are promoted at an age – four months– when babies should be consuming breast or formula milk.

U.S. researchers say that studies designed to find an association between eating a nutrient-dense breakfast and losing weight do not prove that one causes the other. The researchers examined 92 studies that looked at the effect of breakfast on obesity, finding that many were either biased or simply did not advance knowledge about the issue beyond the status quo. They said a number of the research articles tended to overstate the strength of study designs and “ignored evidence that did not support” their hypothesis.

Access to healthy foods, especially fruits and vegetables is often limited in low-income communities. Now a study by a North Carolina medical center shows that community-supported agriculture (CSA) programs that link consumers to a local farm’s produce during the growing season may provide an solution to the problem. The small feasibility study involved low-income women with children evenly divided into an intervention group and a control group. Intervention participants – but not the control group – received a free box of fresh produce for 16 weeks, educational sessions, a farm tour and a grocery store tour. The researchers observed a significant increase in the number of different fruits and vegetables in the intervention households as well as increases in fruit and vegetable consumption.