Random Thoughts of a Dietitian: Post #2
Updated: Nov 24, 2022
"How would eating 300 grams of carbohydrate in a 4-hour eating window, day-in and day-out, optimize your body's ability to use glucose for energy?"
Most dietitians will tell you: The best way to improve blood glucose control and improve insulin sensitivity is to eat small, frequent meals throughout the day. And we know that almost all other health outcomes are somehow tied to healthy blood glucose regulation. This is actually the basis of how I design my clients' programs. But how does intermittent fasting fit into that?
There are some studies demonstrating intermittent fasting's ability to improve blood glucose and insulin sensitivity...but how? How would eating 300 grams of carbohydrate in a 4-hour to 6-hour eating window, day-in and day-out, optimize your body's ability to use glucose for energy?
Is it possible that, by keeping glucose low/beta cells in the pancreas mostly inactive for 90% of the day, we somehow preserve the pancreas' beta cells' ability to secrete insulin rapidly for situations in which a bunch of glucose dumps into the blood? I'm not sure. But there are three main proposed mechanisms of fasting's benefits in relation to glucose metabolism:
1.) Calorie restriction will generally reduce body fat, which is directly associated with increased insulin sensitivity (and glucose utilization, as a result.)
2.) Fasting seems to reduce leptin when compared to a general caloric restriction (a hormone that increases your body’s ability to store excess energy as body fat.)
3.) Adiponectin (a hormone derived from body fat) is indirectly associated with fat storage & insulin resistance (Meaning: Higher levels of adiponectin are associated with reduced body fat/insulin resistance, which is good.) What's interesting: Adiponectin seems to increase with any caloric restriction, but these increases appear greater in those who follow a fasting regimen.
Some might claim to know the answer as a matter of fact, but again, it's all theory at this point. I'm open to, but not convinced of, the potential benefit of intermittent fasting, in comparison to more frequent meals/snacks; especially when considering the risks of intermittent fasting. And just to say it: I am not convinced our body likes to use ketones for energy, even in ketosis (Needless to say, I think combining a ketogenic diet with intermittent fasting is not a good idea for 99% of people.)
"These 'nutritional red herrings' are common & often lead to people feeling like they can never achieve proper nutrition."
People are often overwhelmed by all of the nutrition advice available on the internet. "Don't eat carbs!" "Dairy is bad for you!" "Only eat organic foods!" "Don't eat gluten!" "Avoid GMOs at all costs!" "Vegan is the only way to achieve health!" "Get most of your calories from fat!" If you listened to all the bad advice on the internet, all you'd have left to eat would be ice cubes.
These little details are what I call "nutritional red herrings". They are common & these tiny details often lead to people feeling like they can never achieve proper nutrition. In reality, these commonly referenced tips should probably be near the bottom of a person's priorities, as many of these factors don't actually seem to have a profound influence on health.
Instead, why don't we talk about the more important little details? Example: Overcooking food (especially meat) increases a class of free radicals known as "Advanced Glycation End Products" (AGEs), which can contribute significantly to inflammation/chronic disease risk.
Or that overconsumption of alcohol is associated with dramatic increase in chronic disease, as well as reductions in cognition?
Another detail I never hear about is how calorically dense fats & oils are, regardless of how "healthy" they are. In my experience as a dietitian/nutritionist, virtually nobody understands that fat has more than double the number of calories per gram as carbohydrate and protein. This means: Cooking with an extra 2 tbsp of olive oil could be the only thing keeping you from progressing toward your goals.
This is largely why I think nutrition guidance should be taken more seriously: Armchair nutritionists tell a person to focus on things that aren't actually that important, and often, the cost is the person's ability to focus on things that are actually important.
On the flip side, if I had to pick five small nutrition details for my clients to focus on:
1.) Be conscious of the amount of oil you use, especially at dinner (A good goal for most people is 2-3 tbsp per day.)
2.) Manage your stress by waking up at the same time each day & staying on top of your personal/social/professional responsibilities (This is particularly important if you're also struggling with anxiety/depression.)
3.) Drink at least 80 oz of water each day (barring any health conditions that warrant more/less; CHF, ESRD, etc.)
4.) Start with a breakfast that includes at least 21 grams of protein, 10 grams of fat, and 30 grams of carbohydrate from starch + fruit, ideally. (This is also very important for depression/anxiety.)
5.) The most important: Learn to forgive yourself when you slip. Don't let a mishap on Saturday affect your outlook on Monday. "Perfect" is the enemy of "good", and "good" is all you need.
"We have protein supplements because getting adequate protein through the diet can be a real pain in the butt."
Protein is a crucial part of achieving balanced nutrition; I think we can all recognize that...but why exactly is protein so important?
Protein is so important because it's the only substrate we can use for a number of roles in our bodies, including:
-Rebuilding & growth of muscle tissue (which is crucial for insulin sensitivity/metabolic rate)
-Formation of enzymes that ensure metabolism can take place
-Structural integrity of various cells that make up our bodies
-Regulation of acidity/alkalinity in the body
The problem with natural sources of protein (meat, eggs, etc.) is they tend to be the most expensive group of foods, they're difficult to cook properly (undercooking can make you sick, and overcooking leads to "shoe leather"), they can't be stored at room temperature, you have to chew them a lot (which can be tiresome), they're overly filling, they're bland without marinade/flavoring, and they can lead to constipation if you don't drink enough water/eat enough fiber.
These same reasons are the reason why we have protein supplements. Have you ever needed a starch supplement? Of course not. We don't need starch supplements because starches are cheap, easy to eat, can be stored at room temp indefinitely, and usually taste pretty good with just a bit of salt.
We have protein supplements because getting adequate protein through the diet can be a real pain in the butt. You can cook a 3 oz chicken breast, or throw a scoop of protein powder in some water and shake it up.
Is it ideal to get all of your protein from supplements? No. But I would rather my clients get their protein from a high-quality supplement without heavy metals/artificial sweeteners, than miss their protein goal altogether.
Until next time,
Tim Smith MS, RD, LDN