Intermittent fasting (IF) is a more than just a buzz word--it works! There is great scientific data to back it up, and the physiology of how it works makes sense. We were never meant to have 24/7 access to food, especially highly processed foods. Our pancreas, intestines, liver, and kidneys have to work overtime to compensate for that frequent feeding. Our body was meant to have breaks (fasts) from food where it can recalibrate, process, rest, and pull calories from fat stores. When we fail to give it the opportunity to do so, excess weight, glucose intolerance, and inflammation (often along with pain or belly problems), sets in. Fasting is one of the healthiest and most natural methods I've come across for overall health.
Honestly, I didn't know a lot about it a few years ago--it wasn't "taught in school". My husband had gained some extra weight after we had kids, which he referred to has his "baby weight and dad bod." He wanted to get back to a weight that felt good and allowed him to mountain bike and climb again. He dove into research on IF and then began implementing it, mixing IF with extended fasting to achieve interval weight loss and maintain weight. I soon started doing the same--a few days a week, mostly work days, which has worked well for me.
I have been able to help patients bring cholesterol levels and blood sugar levels and weights down to healthier levels combining exercise, IF, and a lower, complex carb/healthy fat/lean protein diet.
WHAT IS Intermittent Fasting and how do you do it?
Simply put, intermittent fasting (IF) is eating only during certain hours and "fasting" during others. The most popular method is to fast for 16 hours, leaving an 8 hour window when one can eat smart, balanced foods. IF has been used for decades in other countries to help with a myriad of health conditions, ranging from diabetes to joint disease, autoimmune disease and mental health. IF has been gaining a lot of scientific traction and acceptance in Western medicine here in the States over the last decade.
“Intermittent fasting (IF) dates back to the beginning of humankind when no matter how hungry, humans had to be sharp, strong and energized to find, forage or hunt for that next meal,” reports author Lucy Danzier. “Cycling through feast and famine was as natural as cycling through sleep….if all of this sounds barbaric, consider that doctors use intermittent fasting to maintain their weight and energy levels during long, grueling hours of rounds when they need to be alert.”
It’s true. My husband and I are both nurse practitioners who incorporate IF into our daily work lives to maintain healthy weights.
My husband was the one who introduced me to IF. He had gained 20 lbs after we had children and his passion for long mountain bike rides had to go on the back-burner. He came across a book called “The Obesity Code” by Dr Fung, and decided to implement IF. After consistent weight loss, he became a believer, as did I.
I love the interview between Dr. Fung and Lucy Danzier in her article “Keto Is Dead. Intermittent Fasting Is the Latest Diet Trend, and It Burns Fat Faster”.
Here is an excerpt from her article which includes an interview with Dr. Fung, leading physician in medically-supervised weight loss with IF.
“Dr. Jason Fung trained conventionally in internal medicine at the University of Toronto and then practiced nephrology—the study of kidney diseases such as diabetes and cancer—while at UCLA. Fung learned first-hand from his patients that obesity creates type-2 diabetes and that diabetes, in turn, leads to kidney failure and then dialysis.”
In the interview with Danizer, Dr. Fung writes "At first, I practiced like every other doctor practiced in treating Type 2 Diabetes. What we were doing was treating patients with medication and insulin and it didn't work. I realized that what we were doing was treating it backward. The causality goes from obesity to diabetes to kidney disease and then dialysis. So we have to treat the obesity -- not the kidney failure -- because if you treat obesity then you can reverse type-2 diabetes. I know this because I tried it. And my patients who did it got better. So that's when I started to look at the hormonal underlying or underpinning reasons -- why are so many people obese. It's not about calories. The body isn't having a response to calories. In fact, 100 calories of soda vs. 100 calories of salmon -- the hormonal response to those are not the same at all. Our bodies respond to hormones. The effect of grilled salmon vs. cola or cookies on your body is completely different.
"Predominantly, we are talking about the insulin response in your body. Insulin tells the body to store fat. When you eat, insulin response goes up, and it tells the body to store excess blood sugar as fat. When you don't eat, like when you sleep, insulin levels fall. So you have to mobilize calories from fat to burn energy to live. If you eat too much sugar or too many carbs, you have to store all those calories as fat. After you do that, there is no energy available -- so you go out and eat more. And again, when insulin goes up again, all the new calories are stored as fat.
"Some foods are more fattening and some foods are less fattening. People who eat more salad don't get fat while people who eat more cookies and cake (or any sweets) do get fat. So, the next step is to understand how the hormonal response to the type of food you eat tells your body to store fat or not store fat. This is why people care about the glycemic index (GI) of food. The lower the GI, the less your insulin response spikes.
"If you never let your insulin drop then you never tell your body to pull calories from fat. So there is a whole movement among athletes to training in the fasting state. If you train without eating, then you need to pull calories out of storage to get through an intense workout. If you eat in the morning -- let's say you have a muffin before your workout -- then you use up that source and your body never uses calories from fat and your workout was not effective if the reason you're working out is to lose fat.
"So I started to understand more about insulin. At that point, when I started my studies on Type 2 Diabetes patients, there hadn't been a lot of people talking about it and I started thinking about fasting. If you want to drive your insulin low then that's going to involve fasting. And I thought 'That sounds like a bad idea.' But then I realized that there is a misconception that your body slows down. That does happen on a low-calorie diet, but not when fasting. You're switching your body over to a new fuel system.
"People who cut their calories and go on a low-fat diet are losing all the dietary fat. If you do that and lower your calories to 1,500 -- you may be lowering your intake but since fat has no effect on insulin, if you have 1,500 calories of bread or pasta, the carbs still stimulate an insulin response. But, if you eat whole foods that have fat, such as avocado, it won't stimulate insulin.
"If you fast, and don't eat at all, for 12 or 14 or 16 hours, then your insulin is going to fall-- therefore, your body is going to switch over and naturally burn fat. So your body wants 2,000 calories a day, and your body has maybe 200,000 calories stored (as fat). So your metabolic rate doesn't fall, even without exercise. You just start to burn all those stored calories from fat.
"When we asked patients with Type 2 Diabetes to participate in fasting 24 hours, three times a week, they lost weight and got better. They even got off their meds. And it happened so fast.
"Typically people eat breakfast at 8 am and dinner at 6 pm and in that case, we are already fasting 14 hours a day without thinking about it. In the 70s they ate supper earlier. Even if you eat breakfast at 7 am and dinner at 7 pm then you're fasting at least 12 hours a day. This acknowledges that you're supposed to eat in a cycle. There is a certain number of hours in a day when you are supposed to be eating and a certain number of hours when you are supposed to be fasting.
"If you throw your body out of balance and eat from the minute you get up until the minute you get in bed, then you're only fasting for 8 hours