by W.Gifford-Jones, MD
Why is it that some people eat to their heart’s content and never gain a pound, while others gain weight with a glance at the plate? Is there a complex, unseen system that plays a role in weight management for each of us?
Your ability to maintain a healthy weight involves factors beyond diet and exercise. Some people’s metabolism, or operating system, is faster than others, requiring more energy to run.
But there’s more than speed and efficiency. The gut microbiome contains microbial cells, including bacteria, that outnumber the cells in the body. Having evolved with us for millions of years, they all serve important functions, using us as hosts and interacting with our environment. The conditions of our environment and our interactions with the world affect the microbiome and thus our performance.
It’s a mistake, therefore, to think about weight gain and obesity in simple terms. Similarly, it’s a mistake to equate poor mental health or neurological conditions like Alzheimer’s or depression solely with problems located in the brain. The gut and the brain are intricately connected.
A growing body of research demonstrates that the gut microbiota is a significant environmental factor contributing to obesity, diabetes, and metabolic syndrome. This is the basis for recommendations in favour of diets rich in fruit and fibre. Apples and other fruit contain prebiotics, compounds that support the growth and function of healthy bacteria in the gastrointestinal tract. These prebiotics can change the speed and efficiency of your digestive engine, in turn affecting the performance of other systems and organs.
These alterations in your gut microbiome are important because bacteria regulate how much fat you absorb, thereby affecting your weight and susceptibility to problems such as non-alcoholic fatty liver disease.
Changes in the environment, and thereby in the microbiome, may be an important part of the explanation for the obesity pandemic. Increased use of antimicrobial soaps and sanitizers are killing good and bad bacteria alike and we have become increasingly exposed to environmental pollutants.
Furthermore, studies show that stress triggers changes in the circuits between the gut, the nervous system and key organs such as the brain, heart and lungs. When you are feeling stressed, your body is programmed to focus less on the work of digestion and more on fight-flight or freeze-hide response – the former involving high energy and the latter like a shut down.
Chronic stress can result in sustained poor digestion. It should be no wonder that our systems get out of whack, leading some to gain weight more readily or to suffer other unhealthy consequences.