The obesity epidemic is hard to ignore. The media regularly features stories about some aspect of our national weight-control problem and the American Medical Association recently classified obesity as a disease. One is considered overweight when their BMI is between 25 and 30. About 68 percent of Americans aged twenty and older fall into either the overweight or obese camp because they weigh more than is ideal for optimal health.
All this extra fat is having a huge impact on our health. Today, 30 percent of fifty-year-olds and more than 60 percent of those over sixty-five have at least one chronic disease.
…since the 1980s, there has been an almost 300 percent increase in chronic conditions in children
The maxim that you gain weight when the amount of calories you eat exceeds the amount you burn is generally accepted as fact. But that formula is not the whole story of obesity.
Researchers have discovered, for instance, that when our fat stores are overfilled, our other systems, especially the immune system, go awry. Eventually fat loss becomes even more difficult, which is one reason why overweight people tend to become obese and why obese people get even fatter.
You’re Not Fat Because You Have a Sluggish Metabolism
The myth that one can have a sluggish metabolism has been disproven. Researchers from Finland tracked obese and lean twin pairs and found that while the obese twins’ activity level was low, they had higher total energy expenditure and a higher resting or basal metabolic rate (BMR) compared to the lean twins. This study also revealed that while the obese twins had a faster resting metabolic rate than the lean twins, the obese twins had an impaired ability to burn fat. So it seems that in general, overweight people have problems burning fat.
How Gut Bacteria Are Involved in Fat Burning
New research has demonstrated that bacteria in your intestines play a huge role in fat burning; and our metabolism in general.
Through a somewhat complicated mechanism, our gut microflora inhibits normal production of a protein called fasting-induced adipose factor (FIAF). This protein’s job is to block the transfer of fat from circulating cholesterol particles into adipocytes and muscle. When FIAF is inhibited, more fat gets packed away in fat cells than normal.
It’s also been suggested that bacterial imbalances created by high-fat feeding further suppress FIAF and increase fat deposits. Even more interesting are studies showing that berberine, one of my favorite fat-fighting polyphenols, increases FIAF and curtails fat deposition in adipose tissue and muscle. For weight loss and blood sugar improvements, I suggest 900 to 1500 mg of berberine HCl each day with a meal.
Short Chain Fatty Acids Made by Gut Bacteria Impact Fat Cell Synthesis
“Short-chain fatty acids (SCFA) epitomize the notion that when we eat, our microbes are eating too. The bacteria in our gut ferment our food, synthesizing three main types of SCFA—acetate, propionate, and butyrate—in roughly a 70:20:10 ratio.167 The ratio and amount of SCFA produced is contingent upon the type of microbes in the intestine as well as the type of foods eaten.
A recent study compared levels of SCFA and fecal microbiota between European children and children who live in a rural African village and eat a diet rich in plant fibers with no processed carbohydrates. Among the many differences between these groups, it was observed that children of rural Africa have increased levels of gut microbes, including Bacteroides and Faecalibacterium, which are known to produce healthy SCFA.
These children had nearly double the amount of these anti-inflammatory SCFA in their intestines and in a more balanced ratio among the different fatty acids compared to European children. European children had increased acetate-to-propionate ratio; acetate being a main substrate to synthesize cholesterol and other lipids.
Studies in humans suggest that overweight and obese people have an imbalance of SCFA, possibly too much propionate, which is involved in forming fat cells. This may be due to the high saturated-fat content of the diet, which skews the gut microflora balance. Research does suggest that such a diet reduces the number of bacteria in the gut, while decreasing production of healthy SCFA.
In contrast, studies suggest that propionate and butyrate may offer protection against obesity by increasing gut satiety hormones and reducing inflammation.
Summary and Key Takeaways
Imbalanced gut microbes affect body composition, inflammation, and metabolism in many different ways. The dysbiosis (gut bacteria imbalances) weakens your intestinal barrier and increases the burden of inflammatory molecules. Imbalanced gut microbes also increase the levels of unfavorable secondary metabolites, such as short-chain fatty acids (SCFA) and volatile organic compounds which affect fat cell synthesis and fat metabolism.
Healthy digestion and diets of colorful, high-fiber vegetables, fruits, herbs and spices, such as curcumin, and resveratrol have been shown to favor the proliferation of healthy, fat-fighting gut microbes.
A diet rich in fermented foods and prebiotic compounds from inulin in foods such as onions, leeks, and root vegetables are highly protective because they act like fertilizer for intestinal microflora.
Sanchez, M., Panahi, S., & Tremblay, A. (2015). Childhood Obesity: A Role for Gut Microbiota? International Journal of Environmental Research and Public Health, 12(1), 162–175. doi:10.3390/ijerph120100162