I’ve been busy researching, reading, and compiling more information from scientific studies done on intermittent fasting and its potential benefits. This is part two, but you can go here to read about more research on fasting or here if you’re not sure what intermittent fasting is all about.

Can intermittent fasting…

…improve blood sugars and prevent/manage diabetes?

• Animals that ate intermittently exhibited resistance to diabetes and improved blood glucose and insulin sensitivity, even if they did not achieve caloric restriction (Anson et al 2003; Duan et al 2003)
• Animals on daily caloric restriction have lower fasting blood glucose, fasting insulin, reduced inflammatory markers, and improved insulin sensitivity (Lane, Ingram, Roth 1999; Imai 2010; Hursting et al 2003; Lane et al 1995; Wang et al 2007; Bonkowski et al 2006; Okauchi et al 1995; Walford et al 1999; Walford et al 2002; Wang et al 2007; Kalani et al 2006)
• Human results on intermittent fasting are mixed:
  • One study found no change in glucose but lower fasting insulin after 22 days of intermittent fasting (Hielbronn et al Jan 2005).
  • One study found that, while fasting, subjects with diabetes had higher blood sugar levels (Saada et al 2010).
  • Another found that after 22 days of intermittent fasting, women’s bodies showed more difficulty clearing blood glucose but that there was no difference in men. Men also had a decreased insulin response, but women didn’t. (Hielbronn et al Mar 2005).
  • Another study found no change in glucose or insulin in men after 14 days of intermittent fasting (Halberg et al 2005).
  • Two studies found that in humans, insulin sensitivity is more improved with fasting than with caloric restriction (Varady & Hellerstein 2007; Harvie et al 2010)
• Humans on caloric restriction showed lower fasting insulin levels, improved insulin sensitivity, and lower blood glucose. (Hielbronn et al 2006; Weiss et al 2006; Fontana et al 2004).
• The boiled-down verdict: Animals show improvements in blood glucose, insulin sensitivity, and resistance to diabetes with both intermittent fasting (without caloric restriction) as well as caloric restriction (without intermittent fasting). In humans, research on intermittent fasting and blood sugars delivers mixed messages, which probably means there are other factors involved that we don’t understand yet. There might be a gender difference in the blood glucose response to intermittent fasting. Several studies showed that daily caloric restriction can improve fasting insulin levels, insulin sensitivity, and blood glucose in humans.

…treat asthma?

• In one study, intermittent fasting reduced airway resistance, reduced inflammation, and improved the medicinal effects of albuterol in patients with asthma. (Johnson et al 2007)
• The boiled-down verdict: We need more research, but intermittent fasting may have some promising benefits for those with asthma.

…decrease risk of heart disease?

• In animals, caloric restriction has led to lower triglycerides, better cholesterol panels, and reduced inflammatory markers (Edwards et al 1998; Wang et al 2007; Kalani et al 2006; Lane, Ingram, Roth 1999).
• Animals on intermittent fasting and caloric restriction have lower blood pressures and heart rates (Tikoo et al 2007; Wan et al 2003; Lane, Ingram, Roth 1999; Wang et al 2007; Fontana et al 2004; Mager et al 2004).
• In humans, similar improvement is seen in cholesterol, inflammatory markers, and blood pressure with caloric restriction via intermittent fasting (Harvie et al 2011, Varady et al 2009; Walford et al 1999, Walford et al 2002).
• The boiled-down verdict: It seems you can protect your heart with lowered cholesterol, inflammation, and blood pressure by reducing calories, either by eating a little less every day or by intermittent fasting.

…slow cancer?

• Animals that eat intermittently exhibit slowed tumor growth, improved the effectiveness of chemotherapy, and reduced side effects of chemotherapy (Berrigan et al 2002;Lee at al 2012).
• In mice, intermittent fasting without caloric restriction reduced the occurrence and growth of lymphoma (Descamps et al 2005).
• Several studies show that animals with tumors had slower tumor growth and lived longer when calorically restricted with adequate protein, vitamin, and mineral intakes (Weindruch et al 1986; Pashko & Shwartz 1996; Pugh et al 1999; Imai 2010; Hursting et al 2003); however, one study showed mice had no slowing of tumor growth when on caloric restriction (Keenan et al 1997).
• Reviews of animal research conclude that the cancer prevention/slowing benefits are similar between intermittent fasting and calorie restriction (Varady & Hellerstein 2007).
• The boiled-down verdict: Research on the benefits of caloric restriction for cancer is mixed. Intermittent fasting may slow tumor growth and improve the effects of cancer treatment in animals. We need more research to know how these effects may transfer over to humans.

There are a lot of health claims around the benefits of intermittent fasting. As there is so much to say about this topic, I had to split the research into two parts. I am sure this is nowhere near a comprehensive compilation, but I have done my best to boil down the results of a variety of research studies on the potential benefits of intermittent fasting.

One major thing to note as you read through this is that there are a lot of documented health benefits to eating less than we usually do, or in scientific terms, caloric restriction. Most studies on intermittent fasting restricted intakes to 0-50% of the participants’ calorie needs for 2-4 days per week. On the rest of the days, they could eat as much as they wanted. Some studies on intermittent reported subjects overall caloric intake, others didn’t, so it can be tough to make that distinction. In general, when animals are on an intermittent fasting regimen, they eat enough on feeding days to compensate and usually do not end up restricting calories (Anson et al 2003; Descamps et al 2005). Humans, however, usually do not eat enough to compensate and end up restricting calories via intermittent fasting (Harvie et al 2011; Heilbronn et al 2005; Catennaci et al 2016). In other words, the results in many of the human studies could be based on the fact that calories were restricted by fasting, not by anything special about fasting itself. We need more research to distinguish between the two!

Can intermittent fasting…

…cause fat loss?

• Animals on both intermittent fasting and caloric restriction lose fat (Anson et al 2003; Lane, Ingram, Roth 1999; Pashko & Shwartz 1996; Duan et al 2003). One study on mice showed that even though the mice on intermittent fasting averaged the same amount of calories as the normally-fed mice, they did weigh a little less (Anson et al 2003).
• Humans lose fat with intermittent fasting too, though most humans who followed intermittent fasting ended up eating fewer calories overall, also achieving caloric restriction (Harvie et al 2011; Heilbronn et al 2005; Catennaci et al 2016). It is relevant to note here that in studies that asked subjects about their hunger levels, subjects were more hungry on an intermittent fasting diet.
• In one study, women who restricted calories via intermittent fasting lost more body weight than women on daily caloric restriction (Harvie et al 2013). In both cases, their calories were restricted.
• One study found no difference in metabolism (measured by resting metabolic rate (RMR)) between those who had intermittently fasted and those who did not (Heilbronn et al 2005).
• Studies on caloric restriction show that subjects tend to lose muscle mass while losing fat, but can prevent this by eating a high-protein diet while restricting calories (Piatti et al 1994). Two studies have shown that while intermittent fasting, subjects lost fat and were able to maintain muscle mass while eating a lower protein diet (Bhutani et al 2010; Catennaci et al 2016).
• The boiled-down verdict: Fat loss can be achieved by eating less overall, either through eating a little bit less each day or fasting (eating ~25% of your daily needs) every other day or a couple of days per week. Based on limited research, it seems you can maintain muscle while losing fat, either by restricting calories and eating plenty of protein, or by restricting calories using intermittent fasting. It’s possible that weight loss could be faster when calories are restricted via intermittent fasting, but more research is needed to confirm that.

…preserve brain function?

• Animals that eat intermittently experienced slower progression of age-related memory loss and  neurodegenerative diseases (Parkinson’s, Hungtington’s, and Alzheimer’s) (Anson et al 2003; Halagappa et al 2007; Duan et al 2003). This is also seen with caloric restriction in both animals and humans (Imai 2010;Hursting et al 2003; Pitsikas et al 1990; Halagappa et al 2007; Yu and Mattson, 1999).
• Mice on calorie restriction via intermittent fasting had less brain damage during and after a stroke than mice who ate all they wanted (Arumugam et al 2009).
• The boiled-down verdict: In mice, it’s possible to prevent and slow brain aging, damage, or diseases by eating less overall, either through eating a little bit less each day or fasting every other day. We need more research to know how this applies to humans.

…help you live longer?

• Animals that eat intermittently (every other day) can live more than 30% longer than those who eat daily (Goodrick et al. 1983; Anson et al 2003,  Duan et al 2003).
• Mice lived 35-60% longer when on caloric restriction but meeting protein, vitamin, and mineral needs (Weindruch et al 1986; Imai 2010; Hursting et al 2003; Canto & Auwerx 2009; Keenan et al 1997, Pugh et al 1999)
• The boiled-down verdict: As long as macronutrient, vitamin, and mineral needs are met, both intermittent fasting and caloric restriction can promote longevity in animals. Human research on longevity is really tricky (and expensive), so that’s lacking.

Check out this post to learn about the research on intermittent fasting and diabetes, cancer, asthma, and more!

Intermittent fasting is a big time buzz-phrase these days. I see people posting about it on Facebook and Instagram, some of my fitness-savvy friends advocate for it, and I read an article about it in Women’s Health magazine. I’ve seen a teensy bit of research floating around but I’m ready to dig in and really see what it’s all about and whether or not it’s something I might incorporate into my practice.

Today I started my own intermittent fasting experiment. I will be trialing an intermittent fasting lifestyle for the next 3 weeks to practice it, research it, and teach you about it! Along the way, you’ll get all the details of how I’m feeling, whether or not my weight, measurements, blood pressure, or heart rate change, and how cranky I am (I’ll let my husband score that one – for objectivity’s sake). For today, let’s go over some basics of intermittent fasting:

What is intermittent fasting?

Boiled down, intermittent fasting basically means alternating between eating normally and restricting your food intake on a regular schedule. This manifests in many different styles. Some of the more popular protocols are detailed here:

• 16:8 or 20:4 – This is a daily goal to limit time spent eating during the day, making the nighttime fast longer. In a 16:8 schedule, people fast for 16 hours each day and limit their eating to an 8-hour window each day. This is the protocol I will be using. In a 20:4 schedule, people fast for 20 hours per day and limit the eating window to 4 hours.
• Alternate-day Fasting – I’ve read about a few different schedules under this name, but the most common is a 5:2 schedule. In a 5:2, you would eat normally 5 days of the week, and 2 days during the week (you can split them up) you fast entirely or restrict intakes to 500 calories per day.
• Extended Fasting – In extended fasting, folks avoid eating or restrict the types of foods they eat for longer periods of time, anywhere from 2 days to several weeks or months.

Can you eat anything during the fasting period?

That depends on the type of protocol you’re following, but best I can tell, most protocols recommend only calorie-free beverages like black coffee, tea, or water during the fasting period. Anything with calories breaks the fast.

Are there limits to what you can eat during your eating window?

Generally, no. Most websites and researchers recommend eating healthful foods, of course, but there are not too many limits. Some protocols advocate for tracking what you eat to make sure that you meet your macronutrient (carbohydrate, protein, and fat) needs during the eating window. Other plans allow intermittent fasters to eat however much they choose. The end goal is to eat as much food as you need, just in a shorter period of time.

What are the benefits of intermittent fasting?

There have been many claims about the purported benefits of intermittent fasting. I’m working through the research on a bunch of them and I will let you know what I find out in a future post (edit: here’s a link to my post on research)! In what I’ve read so far, supporters of intermittent fasting report improvements in:

• Focus, productivity, and mental performance
• Stress resistance
• Longevity
• Resistance to chronic diseases like diabetes, cancers, and Alzheimer’s
• Fat loss, especially belly fat, while maintaining muscle mass
• Inflammation levels
• Blood pressure and heart rate

How does it do all that?

Honestly, I have a bit more research to do in this area but I will keep you up to date as I learn more. In the initial articles I’ve read, the authors credit ketosis as the cause of many of the benefits listed above. When humans fast for or avoid carbohydrates for a prolonged period of time, they basically run out of glucose energy from food, so the liver starts producing ketones to use as an alternative energy source. It’s sort of like a tank of gas on a hybrid car – if the battery runs out, you can run on gasoline instead. What I need to learn now is why supporters of intermittent fasting believe these ketones are so beneficial. I have some reading to do!

What changes will you be making?

I’m starting out by using a 16:8 protocol and setting my eating window from 10 am to 6 pm. There will likely be a little trial-and-error involved, I imagine. I’m keeping my workouts the same (30 mins cardio, heavy weight lifting, and 30 mins yoga 5 days per week) and eating the same types of food I usually do. I expect that I may have to play with my workout schedule a little bit since I haven’t done well with working out on an empty stomach in the past. Tune in tomorrow to see how I did on my first day!

Oftentimes I will have patients with diabetes whose blood sugars are high, and they think, logically, that if they eat very few (or no) carbohydrates, that will help. Unfortunately, they are working against themselves, and here’s why:

The body has what I like to refer to as a savings account of glucose in the liver. When the cells in the body aren’t getting the glucose they need for energy (like when someone skips a meal or when their cells are resistant to insulin), they start complaining all over the body trying to get someone to fix their problem. Word gets to the liver that the cells are starving and he wants to help. The trouble is, liver is a busy guy. He’s got many, many jobs. I often joke that managing this savings account is his “side gig.” He’s not particularly good at it.

In people with diabetes, liver sometimes starts dumping glucose from his savings account into the blood when he doesn’t really need to, and then once he has started…he doesn’t know when to stop. He just keeps pouring and pouring sugar into the blood and before you know it, this poor person who is trying their darnedest to avoid eating carbs in order to get their blood sugars down has a sky-high blood sugar because they haven’t eaten!

It’s the most frustrating thing in the world because it’s totally backwards to what we would naturally think.

Moral of the story: don’t skip meals, and don’t over-restrict carbohydrates! It’s just as important to eat enough as it is to not eat too much to manage blood sugars in diabetes (side note: that’s true for weight loss as well!).

Bonus sub-moral of the story: If you have something frustrating going on with your blood sugars or your weight that you can’t explain, seek out a Registered Dietitian or a Certified Diabetes Educator to help explain all the funky things that your body might be doing without your realizing it! You don’t have to be frustrated and helpless. You can be empowered to better understand your body!

I wrapped up carb counting yesterday, and I would be lying if I said I wasn’t relieved that I don’t have to poke my fingers anymore. I’m glad I did it – I got some good ideas for tips on how to make it hurt less (the side of the finger is the spot!). I did miss my insulin one day – I was on an overnight girls’ trip and thought I brought everything (got my meter, lancets, blood sugar log, and vitamin) but I somehow managed to leave my syringe behind. Phooey. There goes my perfect record.

As far as carb counting goes, it’s not awful. It gets tiresome and Halloween was definitely tough, but it wasn’t the hardest part. Getting the 30 minutes of activity 5 days per week was a challenge, but not the end of the world. Now, getting the 3 minutes of activity per every 30 of sitting – that was the sticker. Fortunately, the apps I discussed in this post made it easier. I’ll be writing a post reviewing the two apps soon! Even with the apps, it was downright impossible to do that every single thirty minutes. You know, I have 60-minute appointments and on girls’ day I drove for two hours there and two hours back. No exercise there. But I did the best I could and honestly, it really felt good to get up and get the blood flowing and joints moving on a regular basis.

As a special treat, my husband and I completed the #DiabetesDanceDare for Diabetes Awareness. Enjoy!

Managing diabetes is a struggle. It can be overwhelming and exhausting to try to keep your blood sugar under control. Here are 7 reasons I think people find it challenging to do the things they know would be good for them:

1. They are confusing. Nobody can agree. You get one recommendation from your doctor, one from an article you read online, one from a library book, and three others from your friends with diabetes. So who’s right? Sometimes no one, sometimes all of them. Diabetes recommendations (and bodies!) are so, so individual. Just because something is recommended for your friend or even the general public, doesn’t necessarily mean it’s right for you. Discuss your questions with your doctor and your dietitian. They should be able to help you weed out what’s right for you.
2. They are overwhelming. So much to do, so little time: checking blood sugars (sometimes 4-6 times a day!), taking medications, dosing insulin, watching your diet, and staying active. I get it – I’m living it temporarily and I’m already starting to wonder how people do this all the time. Managing diabetes is no joke. Sometimes I feel that as health professionals, we throw too many tasks at patients at one time. Be sure to communicate what’s realistic for you and tell your care team if you need to prioritize changes into smaller steps.
3. Presentation is key. Along the same lines, nutrition information for diabetes is often presented in a tsunami of recommendations to idealize someone’s diet and prevent every chronic condition under the sun. I have sat in on and (I hate to say it) helped teach classes that covered carbohydrates, proteins, portion control, fiber, saturated fat, unsaturated fat, heart healthy recommendations, exercise, and mental and sexual health in one mind-numbing three hour stint. How likely is it that those poor people are going to retain anything useful? In fact, I meet with patients on a weekly basis who have attended those types of classes and flat out told me, “I didn’t learn anything. There was way too much information.” My plea to my profession: BREAK IT UP, PRIORITIZE, and EMPATHIZE.

   
   
   

4. Portion does not mean portion. This is a big one. Diabetes educators and dietitians have adopted a term called “diabetes portion” or “carbohydrate portion.” This amount of a food has about 15 grams of carbohydrate and is intended to make carb counting easier. After learning the portions, someone can simply choose 3-4 per meal, 5-7 per meal, or however many their dietitian recommends, rather than track and count grams of carbohydrate. The unfortunate reality is that the word “portion” sends the message that that amount of carbohydrate is all they can have at once. I can’t tell you how many people I’ve worked with who say dejectedly, “So-and-so told me I could only ever have 1/3 cup rice at a time and that’s just never going to happen.” This misconception is suuuuuuper defeating for people who want to manage their diabetes, because they think they have to starve to do it. My solution? Change “carbohydrate portions” to “carbohydrate choices” or something less confusing so people know they can still eat!
5. It’s not black and white. Eating for diabetes is not a list of “good foods” and “bad foods,” which can be confusing. Carbs are not bad and they give us energy, but people with diabetes simply can’t process too many carbs at one time. It’s not total avoidance, it’s moderation. Sometimes that’s hard to grasp.
6. The media. Ohhhhhh the media…so useful in some ways, so full of garbage information in others.
7. It’s a moving target. Recommendations for managing blood sugar are based on a conglomeration of research in the field. You know what that means? New research = new recommendations. Every few years, the recommendations change a bit based on new information. That’s why it’s important, even if you’ve had nutrition education before, to meet with your doctor regularly and a dietitian at least once a year to keep up on what’s new.

For me, snacks are key to carb counting survival. In general, I feel satisfied after eating a carb-controlled meal but I’m finding myself hungry 2-3 hours after the meal. Snack time!

Ideally, a carb-controlled snack for my plan would have 15-20 grams carbohydrate and some protein (even better if it adds in fiber too!). The carbohydrates keep my energy up while protein helps keep the carbohydrates from raising blood sugar too quickly. My struggle is I’m finding the protein portion tough for some reason.

Some of my favorite example snacks include:

• 6-8 whole grain crackers with cheese
• ¼ cup unsalted nuts with 2 Tablespoons dried fruit
• 1 small apple with 2 Tbsp peanut or almond butter
• 3 cups popcorn with a drizzle of olive oil, dash of salt, and garlic powder, rosemary, and thyme (it’s delicious – and even though this one doesn’t have much protein, it’s a whole grain, it’s high in fiber, and the portion is no joke)

My challenge is that often snack time ends up being on my breaks at work, and proteins are either tough to pack or they need preparation and/or refrigeration. I did a stint with mozzarella cheese sticks and they worked out really well but I got a little bored with them. I haven’t been able to make it to Winco to get the bulk mixed nuts at a decent price (I refuse to pay the prices at most grocery stores), and I’ll be honest, I’ve been too lazy to get a little container to put peanut or almond butter in. I could hard boil a bunch of eggs to have ready and take with me, but here again – too lazy, too busy. Gah.

Many times this last week, my snack has ended up being 15-20 grams carb only, without the protein. That’s less than ideal because besides regulating blood sugar, protein helps a snack be more satisfying for longer.

As I gradually add in diabetes recommendations to follow, I have to say that there is a LOT to it. I hear that from my patients all the time, and they aren’t kidding. Remembering to pack a lunch is pretty much habit, but the snacks are often a last-minute afterthought and making sure there’s protein with them seems like a nice idea that only happens when the planets align just right.

Anyway, this is all good experience for me as an RD and it backs up what I hope I communicate to my patients: do the best you can, take one step at a time, and be prepared that life is going to push you back. Life happens. Life gets crazy. Motivation comes and goes. Just be steady and do your best. After all, your life is worth fighting for!