Fad diets come and go. Remember the lemon detox water everyone drank for a couple years? Or the baby food diet (thankfully that one didn’t last too long), or the one that had people slurping up cabbage soup every day? Good times. Today we have a new batch of trendy diet options ranging from major restriction (Whole30) to fat-loading (keto) to strategic timing, AKA intermittent fasting.
Today, with help from a nutritionist and a gastroenterologist, we’re deep-diving into the topic of intermittent fasting. Keep reading to learn what intermittent fasting is, how it’s supposed to work, what its potential drawbacks are, our experience with it, and whether it gets the expert stamp of approval.
What is Intermittent Fasting?
The basic premise of intermittent fasting is that it’s an eating cycle where you avoid eating for a certain period of time (fast) followed by nourishing the body for a period of time. It’s kinda like a non-diet diet because there aren’t any crazy rules about what you can eat, just a timeframe that you should eat within. There are a few different variations of intermittent fasting:
16:8 Method: Fasting for 16 hours and eating for eight hours. For example, have your first meal at 12:30 pm and make sure you have your dinner before 8:30 pm.
Eat-Stop-Eat: Fasting for 24 hours once or twice a week.
24-Hour Alternating Fast: Fasting for 24 hours (or eating very minimally), eating normally for 24 hours, and then repeating.
5:2 Diet: Eating 500 to 600 calories on two non-consecutive days of the week and eat normally the other five days.
Warrior Fast: Eating very minimally (if at all) during the day and only eating a large meal in the early evening.
The idea is more about structuring eating/fasting time versus dictating what you eat, which makes it very different from other types of diets. That said, many people do choose to eat cleaner or follow another diet in addition to intermittent fasting.
“Intermittent fasting should be followed for only a short period of time and, as with everything in nutrition, it should be individualized,” says Tony Castillo, a licensed dietitian nutritionist and consultant for RSP Nutrition. “If you are someone who is very active, then intermittent fasting should be something you follow for a short amount of time and not during competitions due to fuel being restricted.”
You might want to try the 16:8 method for just a day or two or a week and see how you like it. If you think it works for you and it feels good, then try it for a month or a few months to reach your goals. Ultimately, listen to your body and be health smart.
Intermittent Fasting Benefits
“Weight management and weight loss are the most common goals with intermittent fasting as it almost automatically reduces people’s caloric intake to create a deficit that would result in weight loss,” explains Dr. Niket Sonpal, a NYC board-certified gastroenterologist and internist. “Many people believe this nutrition cycle helps their metabolism from going idle. More research is needed to confirm this theory, but many experts purport this theory, as well.”
Castillo stresses the point that intermittent fasting can only work for weight loss if you’re eating fewer calories than your body burns – AKA you’re creating a calorie deficit. In other words, it’s important to still eat well and be mindful of calorie intake. If you don’t eat for 16 hours and then eat 5000 calories worth of donuts and pizza, you’ll most certainly gain weight instead of losing. With the 16:8 method, most people skip breakfast (that’s already 200-400 missed calories) and choose to have either a lighter lunch or lighter dinner.
How Fasting Affects Your Body
Both Castillo and Dr. Sonpal add that some research has found positive benefits from intermittent fasting. That includes insulin resistance, lowering cholesterol levels, and reducing inflammation. All the aforementioned can help us maintain good health and longevity. While promising data, it’s important to note that research on intermittent fasting is relatively young so there’s still a lot to learn.
Insulin levels drop: As we eat, our insulin levels increase, however, when fasting they drop and lower levels of insulin have been shown to improve your body’s fat-burning capacity.
Norepinephrine movement: When you fast, norepinephrine is sent to fat cells by your nervous system, which helps them break down fat cells to be used as energy.
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Potential Drawbacks for Intermittent Fasting
We’d be remiss if we didn’t talk about some of the potential negatives of intermittent fasting. Perhaps one of the most notable, says Castillo, is that for some people intermittent fasting can trigger an eating disorder such as anorexia (starving yourself) or binge eating. “Having less time to eat can cause people to create unhealthy and unsustainable practices,” he explains.
Another downside is that intermittent fasting causes hunger. A lack of fuel can result in headaches, crankiness, feeling weak or tired, or experiencing brain fog. In other words, it has the potential to disrupt our daily lives – our jobs, our gym time, our family, and social time. Dr. Sonpal adds that intermittent fasting may also be difficult (or even not recommendable) for those on continuous medication treatments.
Our Experience with Intermittent Fasting:
We have found intermittent fasting on the 16:8 method to be one of the easiest ‘diets’ to follow, because you can still essentially eat what you like, within reason. Want a burger for dinner? Okay, make sure you have a healthy lunch and maybe don’t eat all the fries! Of course, if you want to be in a calorie deficit to shift a few pounds, this is one technique, but if you’re not interested in losing weight, then just try to focus on healthy eating and don’t worry about counting calories.
If the idea of not eating before lunch makes you go weak at the knees (we get you!), then you actually might be surprised at how easy you find the 16:8 method. We have found that usually when we eat breakfast, we feel super hungry before lunch. However, when you fast your body doesn’t crave in the same way and you actually feel less hungry. You can also shift around your fasting times to suit you, so if you prefer to eat earlier, you could break your fast between 10 am and 6 pm, as opposed to 12 noon and 8 pm. You can also be a little bit flexible to suit your social plans, so if you go over by one hour a day (15:9), don’t worry too much about it. Similarly, some days you might find that you eat in a smaller time frame, and so you’re essentially doing 18:6.
Finally, we found we had more energy when we did intermittent fasting. It was easier to get up in the morning, and we started our day with a hot lemon water and didn’t even crave coffee until lunchtime (sometimes sooner on a dull day!). Probably one of the hardest things about intermittent fasting is that sometimes your mouth just gets bored, AKA you eat just because you feel like it, not because you’re hungry. So, our tip is to make tasty drinks your thing. Start with a lemon water, have a coffee, drink some cucumber water, try a new fruit tea in the afternoon. Give your mouth things your taste buds will enjoy that won’t involve actually eating – it helps! Check out these delicious healthy drinks.
If you’re someone who exercises regularly, you’ll probably find that the 16:8 method isn’t the best plan for you, as the energy to work out is definitely depleted when you are fasting daily. If you exercise regularly and you want to try intermittent fasting, then try the 5:2 diet so that you can work out on the five days where you are not in a calorie deficit.
Our results: We found that by eating all our usual meals, that when we did the 16:8 method and skipped breakfast and cut back on our naughty snacking habit (so we just ate two meals a day), we were able to lose around 1kg a week for the first few weeks. This was also combined with two to four sessions of intermediate exercise, which in our case, was 40 minutes fast walking on a treadmill at a moderate incline. After about a month of intermediate fasting, our will to be as strict started to decline and our weight loss also slowed. We were happy with the results and would definitely consider this a good ‘detox’ option in the future.
Bottom Line: The reality is that in order to lose weight and nourish our bodies, dietary changes often need to be made. However, there’s a line between what’s good for you and what’s not, and moderation is key. Intermittent fasting can be an effective way to self-discipline and eat more mindfully, but it’s important to listen to our bodies and to make sure we’re nourishing ourselves at the same time.
Would you try intermittent fasting or have you tried it? Let us know your experience in the comments below and what you thought of it.