I may have to retract things I have said in the past. I can’t recall if I’ve ever explicitly stated it in this blog, but for a long time I’ve been a follower of the idea of “If It Fits Your Macos” (IIFYM) dieting.
IIFYM is often summed up in an over simplified manner as ever calorie from every carbohydrate source has the same value to your bodyweight no matter if it’s from rice, grains, sugar, poptarts or icecream. 500 calories of carbs from ice cream has the same weight gain potential to your body as 500 calories of whole-wheat bread.
Now there’s evidence that not only is this untrue in the immediate short term digestion, but over time you can alter the way your body responds to calories and gains weight, even combat obesity. This suggests that obesity might not be solely the result of over eating.
Mounting evidence suggests that the microbiome of the intestines, that is the bacteria in our large intestine that help us digest our food, are responsible for how our bodies respond to intake of certain foods. We have four primary families of bacteria but the most important for our purposes are the Firmicutes and Bacteroidetes.
In those with obesity we see a decrease in Bacteroidetes and an overgrowth of Firmicutes. This may be something they were born with, brought on by environmental factors, or it could be caused by long-term bad diet.
Recent evidence suggests that growth and death of different gut bacteria is in response to our food intake. Firmicutes thrives in a diet high in fat and sugar. Bacteroidetes however feeds on complex carbohydrates, starches and plant matter as well as our intestinal mucins when in a state of starvation. This is a good thing for those looking to control their weight which I’ll explain shortly.
So how can I apply this to weight loss?
There’s a few things you can do to help rebalance your gut bacteria in favor of healthy Bacteroidetes populations.
Eat more starchy fruits and vegetables
This includes potatoes, plantains, green bananas, to name a few. Overall though, there’s not really a wrong answer here. Fruits and vegetables are healthy sources of complex carbs, vitamins and minerals and the more of these you eat the less junk food you’ll have room for.
Bacteroidetes is more resilient to starvation that its counterpart. In a fast bacteroidetes can consume intestinal mucins to stay alive where other bacteria will gradually starve out. I’m not advocating long term starvation diets or water fasts, but healthy intermittent fast for 16 hours a day, or fasts with only green drinks or restricted zero-carb dieting for large portions of the day, even up to 72 hours could potentially effect the balance of bacteria. Remember though, our intestinal bacteria is very resilient and changing it is a LONG TERM plan, so any diet you choose needs to be sustainable. You can’t hope to crash diet your bacteria into the way you want. As soon as you go back to eating sugary, fatty food you’ll go back to the way things were.
Eat LESS junk food
This shouldn’t really need explaining. Junk food feeds the bad bacteria, it’s high in empty calories, low in satiation, and it’s bad for your long term health. Simply reducing your daily intake may not be enough for those with advanced weight gain problems. You need to commit to a lifestyle change for the long term if you want to reap the benefits.