Medical News Today: Supplement may help burn fat long after exercise

Gut bacteria produce an appetite suppressant than can strengthen the effect of an exercise-based weight loss program.

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A supplement may boost the fat-burning effects of exercise long after it has finished.

The many health benefits of regular exercise are well known. However, its impact on weight loss is less clear, as exercise increases appetite, potentially resulting in an increased calorie intake.

A new study appearing in the journal Metabolism presents a possible solution.

The research comes from the Scottish Universities Environmental Research Centre, the Universities of Glasgow and the West of Scotland, and Imperial College in London, all of which are in the United Kingdom.

It suggests that adding a certain appetite-suppressing supplement to moderate exercise increases the likelihood of weight loss, even without a change of diet.

The Biotechnology and Biological Sciences Research Council provided funding for this research.

A fascinating supplement

The study explored a supplement called inulin-propionate ester (IPE).

Propionate is a short-chain fatty acid produced in the digestion of dietary fiber by gut microbes. It is a natural and effective appetite suppressor.

Propionate breaks down quickly in the body, so to strengthen its effect, scientists have chemically bound it to inulin. This is a fiber common to garlic, Jerusalem artichoke, chicory, and onion. The result is IPE.

As corresponding study author Douglas Morrison notes, "There's a great deal of interest at the moment in how our gut microbiota affects our health and well-being."

The scientists' previous research established that the use of IPE as a dietary supplement increased the rate at which the body oxidizes, or burns, fat while at rest.

The research also found that IPE suppresses the urge to consume high calorie foods. As an example, those who the researchers offered all the pasta they could eat wound up eating 10% less than they usually would.

Their new study has revealed that IPE can enhance the weight loss effects of a moderate exercise program without requiring dietary changes.

As Morrison explains, "What we've been able to show for the first time is that this latter effect continues when exercise is added to regular IPE intake." The study did not examine the effectiveness of a weight loss diet plus exercises plus IPE.

The trial consisted of 20 women aged 25–45. Each had a body mass index (BMI) greater than 25. The trial lasted for 4 weeks.

The team divided the participants into two groups of 10. Both groups participated in moderate exercise programs.

One group received a supplement of IPE, and the other received a placebo supplement comprising cellulose. All participants maintained their normal eating patterns throughout the trial.

The researchers measured each person's resting fat oxidation levels both before and after the trial using blood and gas samples. They collected these before breakfast, after breakfast, and after lunch.

The participants who exercised while taking the placebo exhibited no change to their fat oxidation levels after the trials.

The group taking the IPE, however, showed a significant increase in the burning of fat at rest, even 7 hours after their most recent dose of IPE.

Limitations of the study

The new study was small and its duration brief, so its conclusions require additional verification.

Study co-author Dalia Malkova says, "While these initial results are promising, we should stress that there are limitations to this study, which was conducted with a small group over just [4] weeks."

"For example, we can't yet draw any conclusions about how the increased fat oxidation, combined with exercise, might affect participants' body composition and body mass."

The researchers are seeking funding for further trials of IPE, involving more people and for a longer period of time.

Original Article

Medical News Today: Why caffeine may limit weight gain

Consuming caffeine may offset some unhealthful consequences of an obesity-inducing diet, according to a new study in rats.

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Caffeine could counter some weight gain resulting from a diet high in fat and sugar.

Scientists at the University of Illinois at Urbana-Champaign fed rats a high-fat, high-sugar diet. They then gave some of the rodents caffeine extracted from mate tea and others decaffeinated mate tea.

The rats that consumed the caffeine extract gained 16% less weight and 22% less body fat than those that consumed decaffeinated mate.

The anti-obesity effects were similar among rats that consumed synthetic caffeine or caffeine extracted from coffee.

By studying the rats' cells, the scientists found that caffeine exerts some of its effects by altering the expression of certain genes.

They report their results in a recent Journal of Functional Foods study paper.

"Considering the findings," says corresponding study author Prof. Elvira Gonzalez de Mejia, Director of Nutritional Sciences at the university, "mate tea and caffeine can be considered anti-obesity agents."

Caffeine reduced body fat accumulation

The team fed six groups of rats a high-fat, high-sugar diet for 28 days. In addition, they supplemented the diet of five of the groups with one of the following: synthetic caffeine, mate tea containing caffeine, caffeine extracted from mate tea, caffeine extracted from coffee, and decaffeinated mate tea.

The amount of caffeine was equivalent to the amount that humans ingest from drinking 4 cups of coffee per day.

After 28 days, there was a marked difference in lean body mass among the six groups of rats. The rats that had consumed caffeine from any source had gained less body fat than their counterparts in the noncaffeine group.

There was a close link between the storage of lipids in fat cells, the gain in body weight, and the increase in body fat.

The findings add to increasing knowledge about the potential for mate tea to help combat obesity. This is in addition to other health benefits conferred by the vitamins, flavonoids, and phenolic compounds in the herbal tea.

Mate, or yerba mate, is a beverage made from the leaves of the tree Ilex paraguariensis St. Hilaire. It is a popular drink in South America, where consumption in countries such as Brazil, Chile, Argentina, Paraguay, and Uruguay can reach 3–10 kilograms per capita.

The drink has become a popular alternative to black tea and coffee because of its reputation as protective against infection, obesity, diabetes, and cardiovascular conditions.

A typical serving of mate contains between 65 and 130 milligrams (mg) of caffeine. A cup of brewed coffee, in contrast, can contain 30–300 mg of caffeine.

Caffeine altered gene expression

In addition to studying the effects of the various forms of caffeine in live rats, the researchers investigated the effects in cell cultures.

They exposed fat cells from mice to all three types of caffeine: synthetic, coffee extracted, and mate extracted.

These tests revealed that lipid buildup in fat cells decreased by 20–41%, regardless of the type of caffeine.

Examination of genes relevant to lipid metabolism and obesity also revealed that caffeine reduced the expression of certain genes.

Caffeine downregulated the expression of genes that code for fatty acid synthase (FASN), an enzyme that helps produce long-chain fatty acids, and lipoprotein lipase (LPL), an enzyme with a key role in breaking down triglycerides.

All three types of caffeine — synthetic, mate extracted, and coffee extracted — reduced the expression of both genes by a considerable amount.

The cell culture tests revealed that FASN expression decreased by 31–39% and LPL expression decreased by 51–69%.

In the rats, the consumption of caffeine extracted from mate reduced FASN expression in fat tissues by 39% and in their livers by 37%.

The researchers found that downregulation of FASN and two other genes in the rats' livers reduced the production of triglycerides and low-density lipoprotein cholesterol in those organs.

Need for affordable, accessible interventions

The imbalance between the intake and use of energy by the body triggers storage of excessive triglycerides in fat tissues.

The World Health Organization (WHO) defines overweight and obesity as "excessive fat accumulation that may impair health."

Obesity is a major health challenge worldwide. Once confined to higher-income nations, it is now also a growing health problem in middle- and low-income countries. At least 2.8 million deaths per year result from obesity and overweight.

Overweight and obesity are major risk factors for many chronic health conditions, including type 2 diabetes, fatty liver disease, and cardiometabolic diseases.

While various interventions — including lifestyle changes, drugs, and surgery —can help people with obesity lose weight, keeping it off remains a major challenge.
The pressing need for widely available and affordable strategies is encouraging scientists to search for solutions in plants and herbs.

"The results of this research could be scaled to humans to understand the roles of mate tea and caffeine as potential strategies to prevent overweight and obesity, as well as the subsequent metabolic disorders associated with these conditions."

Prof. Elvira Gonzalez de Mejia

Original Article