“Overweight and obesity may soon cause as much preventable disease and death as cigarette smoking,” said Surgeon General David Satcher in his December 2001 “Call to Action to Prevent and Decrease Overweight and Obesity.”
Approximately 300,000 deaths per year in the United States are associated with obesity and overweight, compared to more than 400,000 associated with cigarette smoking. The total direct and indirect costs attributed to overweight and obesity amounted to $117 billion in 2000.
In 1999, an estimated 61% of U.S. adults and 13% of children and adolescents were overweight. Obesity among adults has doubled since 1980, while over-weight among adolescents has tripled. It’s easy to suggest that people follow recommended dietary guidelines to prevent obesity, but the fact is that only 3% of all Americans meet at least four of the U.S. Dept. of Agriculture’s five Food Guide Pyramid recommendations for the intake of grains, fruits, vegetables, dairy products, and meats.
With more attention focusing on losing weight, the market for weight-loss and weight-management products looks lucrative. In 2001, weight-loss pills and liquid meal replacements grew by 20% and 11%, respectively, contributing $3.9 billion to the weight-loss market. In addition, Nutrition Business Journal predicts that sales of weight-loss supplements will continue to grow at a fast pace over the next few years. According to manufacturers, distributors, and retailers interviewed for NBJ’s annual review of the sports nutrition and weight-loss market, weight-loss products have proven somewhat recession-resistant compared to other supplement segments. Despite a slowing economy, they reported no softening in demand.
Here is a breakdown of some ingredients thought to contribute to weight loss that are currently used in weight-related foods and supplements.
Fiber is commonly used in weight-loss products such as bars and beverages. Fiber remains in the digestive system longer, giving a feeling of fullness without the extra calories. “Some fibers, such as inulin, promote good digestive health, adding to a feeling of wellness that encourages staying with the diet,” explained Scott Noar, Manager of Applications & Technical Services, Orafti Active Food Ingredients, Malvern, Pa.
Fiber has fewer calories than other food components, he said. This means that foods higher in fiber tend to be lower in fat and calories. Dieters can eat more of these foods without exceeding their calorie limits.
Inulin is one type of fiber used in several categories of weight products, including bars, powdered drink mixes, supplements, and sugar-free products. In addition to being a source of fiber, inulin has several functional characteristics that add value to weight-loss products, explained Noar. It provides softening in bars, which extends shelf life and helps extend eating quality over time. Inulin can provide up to 10–30% of the sweetness of sugar with only half the calories of sugar. It also helps build mouthfeel and body. In supplements and confections, inulin has excellent tableting properties, compared to other ingredients that have twice the calories. High-protein diets lead to constipation and digestive problems. Inulin combats these issues by promoting good digestive health.
Fenugreek is thought to aid in weight loss. The galactomannan is used for its potency in reducing after-meal blood glucose levels. Recent scientific work conducted with Fenu-Pure 85 (Adumim Food Ingredients, Israel) has shown the galactomannan’s capacity to adhere to fat droplets. A second test conducted in laboratory rats has shown the product’s ability to significantly reduce weight gain in rats and increase the amount of fat in the rat’s excrement. It is postulated that the unique properties of Fenu-Pure arise from its ability to emulsify and encapsulate oils, triglycerides, and cholesterol, and thus significantly limit their absorption into the bloodstream.
Chitosan, chemically similar to plant fiber, is derived from chitin, a polysaccharide found in the exoskeleton of shellfish. It is sold as a weight-loss supplement for its reported fat-absorbing properties. Although chitosan’s fat-absorbing potential is still debatable, companies who sell the supplement explain that chitosan dissolves in the stomach and converts to a gel that “traps” fat. This in turn prevents fat absorption and subsequent storage. Both the chitosan and the fat are excreted in the stool.
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Used predominantly in weight-loss supplements, bars, and beverages, chromium helps the body’s tissues respond efficiently to insulin, allowing glucose to be metabolized for energy. The body requires chromium for the normal metabolism of carbohydrates, fats, and protein.
Numerous studies have evaluated the use of chromium picolinate as part of a healthy diet and/or exercise program, and its ability to reduce body fat, preserve lean mass, and lead to weight loss, said Mary Hudson, Vice President, Market Development, Nutrition 21, Purchase, N.Y. Significant increases in lean muscle mass and/or significant reductions in body fat, percent body fat, and total body weight, have been reported in well-controlled studies.
Most recently, a study conducted at the University of Vermont College of Medicine and reported in the Journal of Nutrition in June 2002 evaluated the differences in carbohydrate and lipid metabolism between obese and lean animals. William Cefalu and colleagues found that the obese animals had impaired metabolism and that the administration of chromium picolinate significantly improved both carbohydrate and lipid metabolism. The enhanced metabolism resulted in superior blood sugar control and cholesterol profiles. In addition, the researchers found that the intake of chromium picolinate resulted in a significant improvement in the metabolic action of muscle cells.
Nutrition 21’s chromium picolinate, Chromax®, recently received Generally Recognized As Safe (GRAS) approval from an independent panel of food and nutrition safety experts. The company currently sells it as a dietary supplement and an ingredient for supplements and nutrition bars and beverages. It also includes the chromium picolinate in its Lite Bites®Fat-Fighting System products, including bars, chewies, shakes, and boosters.
In a randomized, controlled study, two groups of people followed the USDA Food Guide Pyramid, but one group included the Lite Bites products as well. After 12 weeks, the control group lost minimal weight and subsequently gained it back. More than two-thirds of the Lite Bites group lost an average of 7.7 lb over 12 weeks and kept it off. In addition, they preserved their percent lean body mass, while the control group increased their percent body fat and decreased lean body mass.
Soy and Whey Protein
In June, LifeScript, Orange, Calif., a producer of personalized nutrition products, introduced a new weight-loss beverage, SlimScript, a soy-based meal-replacement
drink. “Research has shown that soy is a low-calorie, low-carbohydrate food that possesses the ability to decrease fat storage, increase fat cell metabolism, and process lean muscle mass,” said Edward Geehr, President. “That’s why soy has become an important ingredient in many weight-loss programs.”
Soy protein is often used in weight-loss products because it is a lean protein. According to LifeScript, university studies have documented the effect of soy proteins on fat deposition and lean muscle preservation in menopausal women, even if calories remain the same. Soy by itself seems to lessen the tendency toward fat deposition and prevent the loss of lean muscle mass. And soy will help to retain lean muscle mass, which in turn leads to increased burning of calories and decreased fat.
Whey protein is another lean protein popular in weight-loss products. The whey peptide glycomacropeptide has been reported to stimulate the release of cholecystokinin (CCK). CCK has been shown to be an important regulator of appetite in humans, working directly on the appetite control center of the brain. Following food consumption, CCK is released from cells in the small intestine. Its release reduces appetite by slowing the movement of food from the stomach to promote the feeling of fullness. It also acts on nerves in the stomach lining that tell the brain that the stomach is full.
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L-carnitine transports fatty acids into the mitochondria, where the fat is burned for energy. Although the body makes L-carnitine from the amino acids lysine and methionine, athletes and dieters take L-carnitine supplements hoping to burn fat faster. Supplement manufacturers also add L-carnitine to beverages and nutrition bars.
Ephedra is the most publicized botanical associated with weight loss, but it is somewhat controversial as a result of consumer reports of adverse effects. Ephedra is a thermogenic and a stimulant, meaning that it promotes calorie burning and increases heart rate. In the U.S., sale of nonherbal synthetic ephedrine products is illegal. The U.S. Dept. of Health and Human Services recently funded the RAND Corp. to conduct a comprehensive review of the existing science on ephedrine alkaloids, particularly those in dietary supplements. The review is projected to be finished in early autumn. “The National Institutes of Health will use this information to guide an expanded research effort to better understand the safety of ephedrine alkaloids,” said HHS Secretary Tommy Thompson.
Green tea extract is often used in place of ephedra in weight-loss products for its caffeine content. Green tea may also be useful as a glucose regulator.
University of Chicago researchers reported in the June 2002 issue of Diabetes that an extract from ginseng berries could normalize blood glucose levels, improve insulin sensitivity, and lower weight by helping to reduce appetite. An extract from the pulp of the ginseng berry was injected once a day into mice engineered to be obese and suffering from type 2 diabetes. A daily injection of 150 mg/kg caused the obese diabetic mice to lose more than 10% of their body weight in 12 days. The treated mice ate 15% less and were 35% more active than untreated mice.
Hydroxycitric acid (HCA) is a compound found in Garcinia cambogia, a small fruit from southern India. Studies indicate that HCA may curb appetite, reduce food intake, and inhibit the production of fats and cholesterol. HCA has been demonstrated in the laboratory (but not yet in human trials) to reduce the conversion of carbohydrates into stored fat by inhibiting certain enzyme processes. Animal research indicates that HCA suppresses appetite and induces weight loss.
HCA exerts its anti-obesity effects through its inhibition of the enzyme ATP citrate lyase, playing a critical role in energy storage and affecting the appetite. Glucose from excessive calorie intake is converted into acetyl coenzyme A, via a metabolic pathway involving ATP citrate lyase, and then into fat molecules, which are stored in fat cells. HCA inhibits this process by binding to ATP citrate lyase to reduce the production of acetyl coenzyme A, reducing the body’s production of fat and cholesterol. HCA also increases the ability of the liver and muscles to synthesize and store glycogen, thereby suppressing appetite.
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Conjugated Linoleic Acid
Conjugated linoleic acid (CLA) has been demonstrated to induce a relative decrease in body fat and an increase in lean body mass in several species of growing animals, including mice, rats, hamsters, and pigs. As reported in a 1995 paper in Bioscience, Biotechnology, Biochemistry, when mice were pair-fed high-fat diets with or without CLA for 12 weeks, body fat was significantly reduced in the animals fed CLA (0.5, 0.75, or 1.0%), compared to the controls. CLA reduced body fat within two weeks and increased carcass protein content without affecting the animals’ food or energy intake.
CLA favorably influenced body composition in another investigation, reported in Journal of Nutrition in 1996, in which mice were pair-fed either a high-fat or a low-fat diet with or without 1% CLA for six weeks. In this study, CLA also reduced body fat independent of dietary fat intake.
More-recent findings in mice and hamsters, reported in Nutritional Research in 1997, indicate that the trans-10, cis-12 CLA isomer is largely, if not totally, responsible for CLA’s effect on body composition. How CLA alters body composition is unknown, although multiple mechanisms are presumably involved.
There is little evidence regarding CLA’s effect on body composition in humans. However, a study to explore this possibility has just been completed at the University of Wisconsin. In this randomized, double-blind, placebo-controlled trial involving obese adults who were supplemented with 3 g of CLA/day for six months, CLA reduced fat gain.
Cytodyne Technologies, the U.S. manufacturer of weight-loss supplements, currently uses CLA in its Xenadrine EFX weight-loss nutrition bar. The newly launched ephedrine-free bar contains 21 g of high-quality protein and is fortified with glutamine, key amino acids, and 26 essential vitamins and minerals. Each bar also contains 1.5 g of Clarinol CLA, which the company states has been shown to promote weight loss by decreasing body fat and increasing lean body mass and muscle strength.
7-Keto (3-acetyl-7-oxo-dehydroepiandrosterone) is a metabolite of the hormone dehydroepiandrosterone (DHEA). The most abundant of the adrenal steroid hormones, DHEA serves as a precursor for sex hormones, such as estrogen and testosterone. The capacity of 7-keto to promote weight loss in overweight people was investigated in a double-blind study, reported in Journal of Exercise Physiology Online in 1999, in which participants exercised three times per week for 45 min and ate a diet of 1,800 kcal/day. Each person was given either a placebo or 100 mg of 7-keto twice daily. After eight weeks, those receiving 7-keto had lost an average of 6.34 lb, compared to 2.13 lb in the placebo group. In addition, the percentage body fat decreased by 1.8% in the 7-keto group, compared with only 0.57% in the placebo group. The increased weight loss in the 7-keto group was associated with a significant increase in levels of T3, a thyroid hormone that plays a major role in determining a person’s metabolic rate, although the levels of T3 did not exceed the normal range.
No Magic Bullet
None of these ingredients are touted to be a magic bullet for miraculous weight loss. They may aid in shedding the pounds, but ultimately it is up to the consumer to eat a balanced diet and exercise regularly.
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Healthy Oil Helps Lose Weight
Enova™ oil is a 1,3-diacylglycerol oil that affects post-meal blood lipids, body weight, and body fat in a healthy manner. Studies in Japan and the U.S. have shown that human subjects experience loss of both body weight and total body fat. Clinical trials have shown that fat mass and weight can be reduced when 10–20 g of this oil is substituted for conventional oil.
It is the structural configuration of the diglyceride that contributes to Enova oil’s uniqueness—the body metabolizes it in a different manner than dietary trigylcerides. Instead of dietary fatty acids being packaged into chylomicrons, the fatty acids from the 1,3-diglyceride are not reassembled into chylomicrons and pass to the liver to be metabolized.
Kao Corp., a leading manufacturer of consumer products in Japan, introduced diacylglycerol oil as a cooking oil in 1999. Since then, it has become a popular selling item with Japanese consumers. Archer Daniels Midland Co. and Kao Corp. have formed a joint venture to bring this oil to the market outside of Asia. Enova oil will be produced and marketed exclusively by ADM Kao LLC.
In early December 2000, FDA notified Kao that it had accepted Kao’s determination of diacylglycerol oil as GRAS for use in cooking oil and vegetable spreads. ADM Kao LLC is actively working on expanding the GRAS categories.
PediaLean™, a new dietary supplement, targets children directly. The weight-control compound is designed exclusively for children and adolescents, according to its manufacturer, Klein-Becker, Provo, Utah. Children ages 6–10 years take two capsules twice a day, 30–60 minutes before lunch and dinner. Children ages 11–16 take 3 capsules twice a day.
The active ingredient in PediaLean is pediatropin, an all-natural, high-density, micronized fiber concentrate derived from the plant tuber Proteinophallus rivieri. The micronization and purification process, and the natural sources of PediaLean, are proprietary to Klein-Becker.
A double-blind clinical trial studying the safety and effectiveness of the product showed that children who used it along with eating a healthy but not calorie-restricted diet and exercising moderately lost 20% of their excess body weight. By comparison, children in the same study who did not take the product but followed the same diet and exercise program failed to lose any significant weight.
Klein-Becker has launched a Web site, www.WeightLossForChildren.com. The online support network allows parents to ask pediatricians, registered dietitians, exercise specialists, and other obesity experts questions about diet and exercise. Parents also receive personalized eating and exercise plans for their children that take into account gender, height, weight, and age.
by LINDA MILO OHR