Having already looked at ingredients scientifically-supported to enhance satiety or boost energy use, we will also look at the controversies surrounding the dairy-weight management link, and how antioxidant plant extracts may help us beat the bulge.
Another area garnering interest is in ‘body-shaping’. A stand-out ingredient is CLA (conjugated linolenic acid), a fatty acid naturally present in ruminant meat and dairy products.
The main players include Cognis with Tonalin and Lipid Nutrition with Clarinol. Both ingredients have numerous studies supporting their potential in the weight management arena. Indeed, a human clinical trial using Clarinol (Int. J. Obes., 2007, Vol. 31, pp. 1148-54) reported an increase in lean body mass of about 0.4kg in the CLA group, over the placebo group. Interestingly, fat mass reduction was localized at the abdomen and the legs. This gives credence to the ingredient's promotional claims to be a body shaper.
The mechanism of action has been well studied: If fat consumed is not used for energy, the triglycerides are taken up by fat cells - a mechanism for which the enzyme lipoprotein lipase is responsible.
CLA inhibits this enzyme, and instead the triglycerides are diverted to the muscle cells to be burnt. Here the CLA induces the activity of another enzyme, carnitine palmitoyl transferase, which is responsible for oxidation and the burning of fat.
The CLA market is expanding, according to a 2007 Frost & Sullivan report, which said the global market is forecast to reach revenues of US$109.9 million in 2013.
Dairy or calcium?
An ongoing area of debate is the role of dairy in weight management. A relationship between dairy intake and weight reduction has been recorded in numerous studies, and dairy industries in Europe and the US have been promoting milk-based products for consumers who want to slim for some time. The subject, however, remains controversial.
There are even splits within the dairy camp, with some arguing that calcium and vitamin D are the active nutrients behind the effects. One of the lead researchers in this are, Dr Michael Zemel from the University of Tennessee, has previously said that dairy can help reduce body fat and that calcium only accounts for about 40 per cent of the effect.
Green tea has been studied extensively for its potential in the weight management category, with the compound epigallocatechin gallate (EGCG) highlighted as a key component.
Three mechanisms have been proposed: EGCG could increase energy metabolism and fatty acid oxidation; inhibit fat cell development (apidogenesis); and/or reduce lipid absorption and increase fat excretion.
It has also been reported that caffeine must also be present as, for EGCG to aid weight loss, a stimulated nervous system is needed.
Going from tea to coffee, Naturex offers an ingredient called Svetol, which is extracted from decaffeinated green coffee. The proposed mechanism of action is that it inhibits the activity of glucose-6-phosphatase, which is responsible for the release of glucose stored in the liver into general circulation. This means that glucose is instead drawn from deposits in adipose tissue, stimulating weight loss.
An exciting and growing area of study revolves around the gut microflora. A breakthrough paper published in Nature in December 2006 (Vol. 444, pp. 1022-1023, 1027-1031) reported that microbial populations in the gut are different between obese and lean people, and that when the obese people lost weight their microflora reverted back to that observed in a lean person, suggesting that obesity may have a microbial component.
A recent study, published in Science Translational Medicine (Vol. 1, Issue 6, 6ra14), advanced this by successfully showing that the human gut microbiota can successfully be transferred to germ-free mice, and that this can then be passed on from mother to offspring.
Researchers from Nestlé Research Center reported in 2008 that modification of gut microbiota may improve the regulation of glycemic control and reverse the insulin resistance that occurs with obesity. Writing in the FASEB Journal (Vol. 22, pp. 2416-2426), Dr. Chieh Jason Chou and his co-workers reported an enhancement of oral glucose tolerance and insulin sensitivity was observed in obese, diabetic animals following administration of antibiotics to modify the gut microflora.
“Our results strongly support the idea that modulating gut microbiota could be beneficial for improving glycemic control and insulin sensitivity,” said Dr Chou.
This series will continue tomorrow with a look at the regulatory issues surrounding weight management.
To read the first part of this series, Asia proving growing market in weight control sector, please click here.
To read Science: Backing up the satiety and metabolic claims, please click here.