Two thirds of adult Americans are overweight. Half of those – one third of Americans – are obese.
Obesity's cause is often linked to an over intake of calories (usually overeating), the kinds of food eaten and reduced exercise. Plus to a lesser degree, genetics, medical conditions, insufficient sleep, and possibly environmental pollutants known as endocrine disruptors that interfere with lipid metabolism.
More Calories Freed
Also under consideration, is the bacterial composition of your gut. When the balance of bacteria in your gut favors the bad bacteria, these bacteria may break down more fiber than your good bacteria do. That can free more calories, which may then be absorbed into your bloodstream. That's bad. So even if two people eat exactly the same meal, the person with the bacterial imbalance may generate more calories from that meal.
And when the bacterial balance in your gut shifts away from healthy, it can lead to a more permeable or "leaky" gut. Leaky gut may contribute to obesity. The undigested food particles, pathogens and toxins that enter your bloodstream through a leaky gut, can be attacked by your immune system, which may promote inflammation throughout your body.
It's reported that obese people have an unhealthy, higher ratio of Firmicutes (pathogenic) vs Bacteroidetes (beneficial) bacteria, than people of healthy weight. One of the possible ways to improve the balance of pathogenic vs beneficial bacteria in your gut is to increase your daily intake of prebiotic fibers.
Changing your diet to include greater consumption of grains, vegetables, fruits and other prebiotic fiber sources can help.