Does Intermittent Fasting Work? We Asked An Expert

If your Instagram newsfeed is filled with a sh*t ton of fitness influencers, then amongst all the sweaty workout selfies and workout apparel discount codes, odds are, you’ve at least heard the mention of intermittent fasting. But what exactly is this scheduled way of eating if it’s not necessarily a diet? Well, to the average person (myself included) intermittent fasting probably just seems like a psycho routine where one only eats in a short window of time throughout the day and starves themselves the other hours all in the name of dropping a few pounds. Well, because I’m curious as to why someone would endure such torture when there’s like a million other ways to lose weight, I spoke to Kristin Koskinen, Registered Dietitian Nutritionist (RDN) and founder of Eat Well Pros—a site that hooks you up with an RDN to help you adapt to new, healthier eating habits and lifestyle changes—about what exactly intermittent fasting is, what it requires, and most importantly: is it even sustainable?

Read on if you’re as skeptical about intermittent fasting as I was, because apparently the strategized way of eating isn’t as torturous as it may sound.

Betches: What is intermittent fasting?
Kristin Koskinen: Simply put, intermittent fasting is the strategy of cycling eating with fasting. Unlike dieting, calorie counting, macro calculating, and food group exclusions aren’t required. Regimens vary, but can include the following:

The Crescendo Fast: 12-16 consecutive hour fast for two or three days a week, on non-consecutive days.

The 5/2 Fast: Eat normally five days a week, for the other two days, eat 25% of your usual intake, allowing at least one day between fasting days.

The 16/8 Method: Fast for 16 consecutive hours per day; all food is consumed within an eight hour timeframe.

What does it do to the body?
The body requires fuel, and its preferred sources of energy are glucose and fat. Protein is an option, but a very expensive one, metabolically speaking. When glucose isn’t available, as during a fasting period, the body uses fat. The human body was not developed to graze, but rather, is well-adapted to deal with the absence of food.

Losing weight from fasting is the result of reduced calorie intake as a consequence of limiting eating hours paired with hormonal changes that occur. Fasting decreases insulin levels. All food, not just carbohydrates, stimulates insulin secretion. Lowering insulin levels has been shown to increase insulin sensitivity, which is important in preventing and managing diabetes, as well as attaining long-term weight loss.

Insulin resistance can lead to pre-diabetes, diabetes, and heart disease. So what is insulin resistance?  Essentially, it’s when the cells no longer respond fully to insulin. Insulin is a hormone, the proverbial key that unlocks cell doors, allowing glucose in from the bloodstream. The backlog of glucose causes the pancreas to produce and send out more insulin to drive open the cell doors. Over time, the beta cells of the pancreas can’t keep up, or wear out, and the person develops diabetes. In the meantime, the excess insulin load has lead to increased weight, which typically deposits around the waist.

What does a typical intermittent fast look like?
A starting fast might be for 14 consecutive hours. That could mean finishing dinner at 7:00pm and eating an early lunch at 11:00am. Water, herbal tea, and black coffee are not restricted. Mornings without food are one thing; without coffee, that’s quite another. Because most of the fast is overnight, you don’t have much time to think about the fact you aren’t eating. For some people, especially those in the habit of eating late into the night, they may find it easier to just go to bed earlier, and that is a win-win. Studies consistently link lack of sleep to excess weight. Sleep for as many of your fasting hours as you can, keeping in mind that seven hours of sleep is considered a minimum, 8-10 ideal, for health and wellness.

Is intermittent fasting recommended for weight loss?
Intermittent fasting has been an effective weight loss tool, especially in overweight or obese individuals. If a person has diabetes or  a history of hypoglycemia, they should consult with their health care provider before starting any sort of fasting program, as fasting will decrease blood glucose levels and medications may need to be adjusted. People with hypertension should also consult with their health care provider before starting a fasting regimen, as blood pressure can become low during a fast, which often presents as light-headedness. Fasting is not recommended for everyone and generally discouraged for those with a history of eating disorders, children, and pregnant women.

If you choose to go the intermittent fasting route, what are some things you should remember?
If choosing to pursue intermittent fasting, it’s important to continue to drink plenty of water and eat nutrient dense foods during the feeding times. Food should be eaten mindfully and slowly, and without the mindset of getting-it-while-you-can or making-up-what-you-lost when fasting.  Before recommending intermittent fasting, I suggest cleaning up your diet. Replace processed foods with whole foods, eat more plant-based foods, cut way back on refined sugars and sweeteners. Then, if you want to try intermittent fasting for weight loss, your nutritional status and improved eating habits will support your success.

How long should someone follow an intermittent fasting regimen?
This depends on the individual. For some people, they find it becomes a part of their lifestyle. Some people hop in and out of fasting routines seasonally, for a few weeks, such as just after the holidays or when favorite jeans are becoming too snug. Each person is absolutely unique and there are always many considerations, including overall health, activity levels, and the quality of their diet. The first step is to clean up your diet as recommended above. Get clearance from your health care provider if you have any health issues or suspect you may. If you decide an intermittent fast is something you want to try, start with a Crescendo fast for 4 weeks. See how you feel, stop if you experience persistent fatigue, high or low blood sugars, dizziness or light-headedness, nausea, vomiting or lethargy.

Images: Toa Heftiba / Unsplash; Giphy (3)

The Mane Betch
The Mane Betch
Kelsi is a New York City girl who loves hair products, vintage fur coats and any drink that contains both vodka and champagne. In addition to Betches, you may have seen some of her work on, Teen and Mane, among other sites! See what your girl is up to on Instagram @Keke_andthecity.