What’s the Deal With Intermittent Fasting? Can I Drink Coffee?

Dr. Christopher McGowan
January 22, 2021

Obesity in America has been on the rise in America since the 1990s, according to the Centers for Disease Control and Prevention (CDC). It is an epidemic that affects more than 90 million people and is responsible for a whole host of comorbidities, such as heart disease, high cholesterol, high blood pressure, cardiovascular problems, and diseases that affect the liver, kidneys, and other organs. This epidemic is thought to cost nearly $150 billion annually in terms of hospital visits, medication, and various methods of treatment. 

Unsurprisingly, a vast and diverse weight loss industry valued at nearly $170 billion has sprung up over recent decades that attempts to help obese adults lose weight and realize a variety of health benefits. Yet with all the time and resources spent on trying to lose weight, it rarely leads to measurable, lasting results. Fad diets and expensive exercise paraphernalia have promised much, but most people remain stuck in the same place. A relatively new concept has emerged in recent years, however, that takes a decidedly different approach to reducing body weight: intermittent fasting.  

What is Intermittent Fasting?

At its core, intermittent fasting is a type of diet that involves cycling between a fasting period (not eating) and an unrestricted eating window. The ultimate goal of this kind of cycling is to reduce daily calorie intake by essentially eliminating a full meal’s worth of calories in a given day. By doing so, proponents argue, you will consume fewer calories, fat burning will commence, and you’ll begin to lose weight because of positive changes to metabolic health, blood sugar, insulin levels, and insulin resistance. 

One of the more interesting aspects of intermittent fasting is that it provides the opportunity to tailor the meal plan based on your own preferences. This is mainly achieved through different combinations of duration and frequency. Though they all can theoretically achieve a similar result, a few popular methods have emerged in recent years that appeal to different people for different reasons:

  • Alternate-day fasting: The alternate-day plan cycles between a full 24-hour fast and a period of unrestricted eating. This means eating normally on day 1, fasting on day 2, eating normally on day 3, fasting on day 4, etc. Because it requires regular full days of fasting, it can be a little intimidating for some people.
  • Periodic fasting: Periodic fasting involves multiple consecutive days of the week of fasting interspersed with multiple consecutive days of normal eating. An example of this is the “5:2” plan that calls for 2 days of fasting followed by 5 days of normal eating. Some alternate versions allow minimal eating (about 25% of your normal calorie intake) during fasting days. 
  • Time-restricted fasting: The most popular intermittent fasting plan uses time-restricted fasting that is divided up into fasting and eating periods within the course of a single day. The most common type is the “16:8” plan that involves 16 hours of the day devoted to fasting followed by 8 hours of normal eating. 

The main goal of opting for one of these plan types is to determine a schedule of fasting that you can reasonably sustain over an extended period of time so that fat loss can happen continually. For many the 16:8 plan is the least onerous because it essentially only requires skipping breakfast each day; in that routine, a person can begin eating at lunch time and then finish eating for the day after an 8 hour window. 

Are There Certain Things I Can’t Eat or Drink, Like Coffee?

As with all diets, many questions about intermittent fasting revolve around what you can and can’t eat. What’s somewhat unique about intermittent fasting, however, is that there are essentially no restrictions on the specific type of food or beverage you consume during the period after you have fasted. A major caveat: if you eat more calories than you burn during the feeding window, you won’t lose weight. So even though you can eat or drink anything, the type, content, and quantity of food are all still factors in whether or not you’ll lose weight.

What about coffee, though? This is one of the most common questions about intermittent fasting, and the good news for coffee aficionados is that coffee is fully acceptable during both the fasting and feeding windows. However, in order to get the continued benefits of the diet, you’ll have to switch to black coffee during the fasting period; artificial sweeteners (like stevia or aspartame), creamer, and other carb-friendly additives have calories and sugars that can affect insulin sensitivity and counteract the metabolic benefits of the fast (this is similar to the effect on ketosis in a keto diet or other low-carb style diets). So if you’re used to your morning latte or cappuccino, you’ll need to switch to black coffee, which has very close to zero calories.   

Does Intermittent Fasting Actually Work?

Like many other diet plans, there hasn’t been enough research done to date to make a definitive conclusion about the true efficacy of intermittent fasting. Nevertheless, most of the preliminary research does actually provide some evidence. For example, a National Institutes of Health (NIH) study showed that lab animals had a longer lifespan and were leaner when they were subjected to periods of fasting intermixed with regular feeding. The researchers behind these animal studies have suggested that the cellular “stress” that accompanies periods of fasting is similar to the stress that happens when exercising: the body will grow stronger after it recovers from the stress. 

Also, a systematic review of a series of clinical trials in Australia indicated that “intermittent fasting is an equivalent alternative to continuous energy restriction for weight loss.” In other words, intermittent fasting worked just as well as “normal” diets that require you to reduce caloric intake at every meal. The study pointed to the tendency of the body to conserve energy (and thus reduce weight loss) when on a diet defined primarily by calorie restriction; by contrast, periods of fasting can counteract that tendency and end up improving weight loss. 

So even though the evidence isn’t 100% conclusive at this point, it appears to be at least comparable to other methods of weight loss. As more studies are done, it may prove even more reliable. Overall, it would be most accurate to say that it isn’t “better” than other diet plans; rather, it can be more effective for people with certain preferences. Another way to put it: if you have a higher tolerance for skipping meals, intermittent fasting might be more effective than other diet plans. 

Are There Any Risk Factors or Side Effects to Intermittent Fasting? 

For all its potential benefits, intermittent fasting does have some pitfalls to be aware of. For one, the long stretches of fasting may be unrealistic for people who are accustomed to eating smaller meals at routine intervals. Similarly, it might actually be dangerous for people with chronic diseases like type 2 diabetes who can’t take their medication on an empty stomach. Some other individuals for whom intermittent fasting would be inadvisable are:

  • pregnant women
  • adolescents in an active growth phase
  • people with an eating disorder like anorexia or bulimia
  • people on medications with required regular eating patterns

Another possible concern to be mindful of is related to one’s eating habits during the non-fasting cycle of intermittent fasting. At a fundamental level, intermittent fasting works because of an overall reduced caloric intake on a week-by-week basis through routine eating and fasting cycles. Because the food intake part of the cycle is meant to be unrestricted eating, there can be a temptation to overeat when not fasting. This, of course, would counteract any benefit from the fasting period. For this reason, it is important to eat healthy foods in the same amounts in the eating phase that you did prior to adopting the plan. 

Diets Aren’t for Everyone

Coffee drinkers may be excited to learn that intermittent fasting allows coffee consumption during the fasting window, but the truth is that most people still struggle with losing weight regardless of how seemingly convenient it is (or how many cups of coffee it lets you drink). The traditional methods of restrictive dieting and punishing exercise regimens most often don’t lead to the kinds of results people hope for. Even if they do lose some weight, they find the new habits unsustainable over the long term, and many people end up gaining all the weight back or even adding to it. 

Helping people end this futile cycle is the driving force behind what we do at TrueYou Weight Loss. If you’ve tried various diets before and have been frustrated by either having short-term success or losing no weight at all, we offer an alternative that can finally help you lose the weight you want to lose and live the life you want to live. Our cutting-edge, non-surgical weight loss procedures like ESG and ORBERA® are designed to finally free you from this futility. If you’d like to learn more, contact us today to request a consultation.

Dr. Christopher McGowan
Dr. Christopher McGowan

Dr. Christopher McGowan, MD, a leader in endobariatrics, specializes in non-surgical obesity treatments and is triple-board-certified in Internal Medicine, Gastroenterology, and Obesity Medicine. Renowned for pioneering endoscopic sleeve gastroplasty (ESG) with over 2,000 procedures, his global influence and research contributions define him as a top expert.

Get Monthly Updates About Nutrition and Advancements in Weight Loss

You might also be interested in:

Learn more about our non-surgical weight loss solutions with a quick consultation.

0% interest financing available.
Discover which solution is right for you.
Go over pricing & payment options.

Fill out the short form to learn more!

Request a Free Consultation

Subscribe to our newsletter for exclusive insights, success stories, and expert tips on non-surgical weight loss. Join our community and stay informed on the latest advancements in endobariatric procedures.
 True You Weight Loss | All rights reserved