Thursday, August 25, 2016

The Science On Fat Loss


1) High Protein Intake Plus Intense Exercise Causes Rapid Fat Loss
Caloric restriction, high-intensity weight training and intervals, and high-protein diets caused substantial changes in body composition in only four weeks— according to scientists from McMaster University in Hamilton, Canada led by Stuart Phillips and Thomas Longland. Test subjects cut calories by 40 percent and consumed either 1.2 grams of protein (LP, low protein) or 2.4 grams of protein (HP, high protein) per kilogram of bodyweight per day. Both groups performed intense exercise six days per week. The high-protein group lost almost 11 pounds of fat and gained more than 2.5 pounds of lean mass in four weeks, compared to nearly eight pounds and 0.2 pounds, respectively, in the low-protein group. The study showed that high-intensity exercise plus caloric restriction triggers substantial changes in body composition and strength, and that the changes are most significant during a high-protein diet. (American Journal Clinical Nutrition, published online January 27, 2016)

2) Brown Fat: The New Frontier for Fighting Obesity
The human body contains small amounts of a calorie-burning tissue called brown fat (brown adipose tissue, BAT) that converts food energy directly into heat. White fat does the opposite— it stores energy. BAT is an important heat-generating tissue that helps animals and humans adapt to the cold. Individual differences in BAT content and activity play important roles in human obesity. A review of literature led by Antonio Giordano from the University of Pavia in Italy concluded that converting abdominal fat to BAT might result in a breakthrough in the obesity epidemic. Increasing brown fat activation helps people expend more calories and burn more fat. Key nutrients, such as L-arginine, L-citrulline and L-glutamate, can increase brown fat activity, which will increase caloric expenditure and promote fat burning. Scientists are actively seeking drugs to turn on brown fat and promote weight loss. (Nature Reviews Drug Discoveries, published online March 11, 2016)

3) Adherence to the Mediterranean Diet Is Linked to Lower Abdominal Fat
People who strictly follow the Mediterranean diet tend to have lower body mass index (a measure of the proportion of weight to height) and waist circumference – according to a large population study led by Simona Bertoli from the Nutritional Research Center in Milan, Italy. The Mediterranean diet is high in fish, fresh fruits and vegetables, lean meats, olive oil and other mono and polyunsaturated fats and whole grains. This diet reduces LDL (“bad”) cholesterol, and maintains blood sugar levels on an even keel. The diet does not affect insulin resistance, but maintains daylong insulin and blood sugar concentrations at lower levels for extended durations. We have good evidence that the Mediterranean diet promotes metabolic health, prevents obesity and may increase longevity. (Clinical Nutrition, 34: 1266-1272, 2016)

4) Green Tea Extract May Be Toxic to the Liver
Green tea extract contains a chemical called epigallocatechin-3-gallate (EGCG) that promotes weight loss by boosting thermogenesis (increased calorie burning) and curbing appetite. Green tea extract is a popular weight-loss supplement, but it could be toxic to the liver— according the Norwegian Food Safety Authority. They have received at least 20 consumer complaints linking the supplement to liver damage. Animal and human studies have found links between EGCG and liver damage in people with metabolic diseases. Obese people often have poor metabolic health, so they might experience side effects from green tea extract when they are trying to lose weight. You can reduce the risk of liver toxicity by avoiding these supplements or taking them with meals. (Nutraingredients.com, March 18, 2016)

5) Low-Carbohydrate Diets Produce Minimal Long-Term Weight Loss
A meta-analysis of 14 randomized, controlled studies by researchers from the Graduate School of Medical Science in Kyoto, Japan found that the average 12-month weight loss in people following low-carbohydrate diets was only 1.54 pounds, and the average fat loss was 1.7 pounds. Harvard University scientists estimate that at least 45 million Americans go on weight-loss diets every year, and the vast majority fail. The goal of a weight-control program should be to lose body fat and maintain the loss. Quick-loss regimens often result in the loss of muscle tissue and do nothing to instill healthy, long-term dietary habits to maintain the new weight. Interestingly, even those who rely on the most popular structured programs to lose weight (e.g., Weight Watchers, Jenny Craig) give praise and credit to those companies when they reduce weight and fat. Unfortunately, these same people regain the modest weight loss after about one year on the program, and then blame themselves for the failure. This sets them up to rejoin the organization all over again, and they do. That is one of the reasons such programs remain in the lucrative weight-loss business—clients join and rejoin, often many times during a decade! Also, “yo-yo” diets (cycles of repeated loss and regain of bodyweight) are unhealthy, and contribute to coronary heart disease and other metabolic disturbances. Relying on external resources certainly has its place, but most of the initiative must ultimately come from within to alter daily habits. (Obesity Reviews, published online April 5, 2016)

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