Hello dear Osa Community!
I hope you enjoy this round-up of a couple noteworthy things I’m reading and thinking about this week.
First, I want to share a study involving one of my most favorite topics: fiber! If fiber doesn’t already excite you (and that’s understandable!), let’s see if this changes your mind at all.
Recently, a colleague brought to my attention a 2023 study in which a high fiber “Microbiome Enhancer Diet” (MBD) was compared to an isocaloric (meaning, supplying the same calories) “Western Diet” (WD). This study found that when adults ate the high fiber diet, they excreted (read: pooped out) 74-390 calories per day, versus 59-185 calories per day on the WD. This means that over time, without changing caloric intake, a person might feasibly lose weight or have an easier time maintaining a stable weight (i.e., not gaining weight) simply by increasing fiber with whole foods. The authors hypothesized that this effect of fiber on energy balance was mediated by changes in the gut microbiome. How? The true explanation is likely complex and not completely understood, as it goes with the human body! We do know that our gut microbiome consumes resistant starch and fiber, producing short-chain fatty acids which are absorbed instead of all the calories from the carbohydrates. (Short chain fatty acids also help keep our intestinal cells happy and thriving and improve insulin sensitivity–topics for another time!). And also, as fiber increases, fat digestibility tends to decrease.
Here is a little more context for the study:
Participants were 12 adults with a mean age of 30 and a BMI in the normal-to-overweight range, and the study period was 23 days for each diet. The MBD was a diet rich in fiber and resistant starch, supplying 26 g of fiber for every 1,000 calories and 6 grams of resistant starch for every 1,000 calories. For an adult eating about 2,000 calories in a day, this diet would supply roughly 50 grams of fiber and 12 grams of resistant starch (side bar: resistant starch is created when carbohydrate-rich foods like potatoes or rice are cooked and then cooled prior to being eaten). Note that this is indeed a hefty amount of fiber! However, gastrointestinal adverse effects were minimal and similar between the two diets. This was a randomized crossover study, meaning that the participants were first randomized to either the MBD or the WD and then–after a 2-week “washout” period–they switched. So all participants consumed both the MBD and the WD, and each person’s results on the MBD intervention were compared to his/her/their own results on the WD.
You can ready the full study here.
Please note: None of these participants reported gastrointestinal (GI) disturbances or dysfunctions prior to the start of the study. If you do experience GI disturbances, it is a wise to start low and go slowly with any fiber increases (or, consider working with a nutritionist 😉), as fiber can provoke GI discomfort in a system that is not accustomed to it.
Next, some inspiration for your week:
Via Peter Attia, MD, I learned of the story of Richard Morgan, a now 93-year-old four-time world champion rower who did not take up rowing until 20 years ago, when he was a 73-year-old retiree attending a grandson’s college rowing practice. As the story goes, the coach invited him to try one of the rowing machines, and there his love of rowing was born “from nowhere”, in his own words. Despite not exercising much prior to his 70s, Morgan now has the lung and heart function of a person less than half his age. Genetics always has its finger on the scale, but even so, this story is a testament to the fact that we are never “too old” for exercise to have a beneficial effect on our health. I encourage you to question and challenge the notion that declining function is to be expected and accepted with age. You can read the Washington Post article on Richard Morgan here and the case report on him here.
Wishing you light and health as you journey through this wintry week.
