Why Intermittent fasting isn't as good as you may think

Fasting diets are increasing in popularity. There are two main types of fasting diets, one is the Intermittent fasting (IF), aka the LeanGains type and the Alternate-Day-Fasting (ADF). These two types of diet are promising to be more effective for weight loss, build muscles and prevent some diseases. Sounds good but may not be for everyone.

On the internet, you can find tones of posts and articles about those two fasting types. Let's be clear, fasting is a fad [1, 2], and as every fad, anyone can write a book about fasting, without even tested or searched more about the topic, just for some quick bucks. So you have to look deeper, in order to find more information about fasting.

Even Terry Crews maintains his body weight with IF

For some people, fasting is way harder to stick with, but they are willing to try it, because they are thinking that maybe they are going to lose more fat easily. But nothing can be achieved easily in our bodies, and this is the same for the fat loss.

Don't get me wrong. Fasting may having many benefits for overall health [3]. But those benefits can be achieved by following a cleaner diet and of course, avoiding processed-plastic foods.

You see, most articles about intermittent fasting usually presenting only the benefits of the fast and stopping there. And as you already know, if you're reading various -health- articles on the net, that most of the writers simply write what everyone else writes, without any personal experiment or further research.

Because I tried intermittent fasting for a year, in this article I will give you the negatives of fasting that most of the articles not saying.

Well, for start, let's view a new study from the University of Illinois at Chicago [4]. In this study a team of researchers set out to determine whether fasting every other day was more effective in weight loss, than simply limiting daily caloric intake.

At the end of the study period, the weight loss observed by those in the ADF group wasn't much different (6%) than those in the daily calorie-restriction group (5.3%). Furthermore, the drop-out rate of participants in the ADF group was a lot higher than those in the calorie-restriction group — 38 percent compared to 29 percent [5, 6].

I tried IF a few years ago and I loved it, because IF fits well into my lifestyle. But I found that skipping breakfast didn't gave me anything more than eating a healthy breakfast. For health improving, the goal should be to lose weight by having quality food and reducing the total amount of calories consumed, rather than focusing on when those calories are consumed [7].

Many fans are saying that fasting can improve metabolism and testosterone levels, but this is not always true [8]. And according to a study [9], testosterone, total leptin and insulin-like growth factor 1 decreased significantly in IF. And fasting may have some negative benefits on muscle growth too, as according to another study [10], short periods of fasting followed by refeeding, as the most people do on IF, promoted muscle fiber atrophy in juvenile Nile tilapia.

With fasting, you might chronically elevate cortisol levels, especially if you already have been tried different diets for years, and your metabolism has already been crashed [11]. And if you rely on coffee to keep hunger away, this might be the worst thing you can do, as coffee promotes cortisol production and weight gain [12, 13].

Let's see the most famous IF protocol, known as the 'Leangains' method. The Leangains program is based on a few simple rules [14].

  • Fast 16 hours every day.
  • Eat within an 8-hour window every day.
  • Exercise with high intensity, a few times per week, often while still in a fasted state.
  • Use 10 g of BCAA before or during your exercise session.
  • On your exercise days, eat 2-3 big meals of protein (meat), veggies, and carbs.
  • Eat your largest meal directly after your workout.
  • On non-exercise days, eat 2-3 meals of protein (meat), veggies, and fats.
  • Eat mostly whole, minimally processed foods, instead of processed foods or supplements.

But as you can see, his approach is based on a whole host of well-accepted and non-controversial practices:

  • High protein intake
  • Low processed food intake
  • Carb cycling
  • Calorie cycling
  • Nutrient timing

Everything of the above has already accepted and confirmed by too many athletes and gym rats. So you don't have to IF, if you follow these practices.

Fasting and hormones

A side effect of certain fasting protocols is that hunger-reducing hormones can get out of balance, leading you to become unresponsive to cues that tell us you’re full and should stop eating.

One example is a short-term study that found that when college women at the University of Virginia fasted for 2 days, they experienced a 75 percent drop in leptin and a 50 percent increase in cortisol. Other studies show that the hormones that trigger eating get amplified in response to fasting [15].

Studies of Muslim women who fast for Ramadan, showed that some women experience alterations in their menstrual cycle from fasting. For example, one study found that prior to Ramadan, 11 percent of women had an abnormal cycle, whereas during the month of Ramadan this number increased to 30 percent [35].

Another study found that Ramadan intermittent fasting has a significant effect on testosterone levels and might be associated with decrease in sexual desire, frequency of sexual intercourse and serum FSH level [36].

The "Leangains" Intermittent Fasting Study

Until recently, there weren’t any studies for the Intermittent Fasting (leangains style), in the way it’s typically practiced and in a group of people who actually lift weights.

The first such study was finally published [37, 38].

The participants were mostly in their late 20s or early 30s, and they all had at least 5 years of training experience. Half of them ate all of their calories in an 8-hour window, with meals at 1 p.m., 4 p.m., and 8 p.m. The other half ate at 8 a.m., 1 p.m., and 8 p.m. each day.

The study lasted for 8 weeks. At the end of the study, the only significant effect observed was for fat mass (FM), where the IF group lost about 1.6kg (about 3.5lbs) of fat versus a nonsignificant loss in the ND group.

However, there were some interesting metabolic and hormonal effects of IF and as I previously noted, most people say nothing about.

Testosterone and IGF-1 levels decreased, levels of several pro-inflammatory cytokines decreased, cortisol levels increased, insulin and blood glucose levels decreased, triglyceride levels decreased, T3 levels decreased and RER decreased slightly. And while the IF group was in a calorie deficit, it was a very small one (less than 10% below maintenance) – probably not a large enough deficit to explain those effects.

Breakfast or Not?

If you are a breakfast eater and want to try fasting, continue having breakfast and not falling on those looking-good-on-paper technics. Fasting may works better on people who already skipping breakfast for years [16, 17], but you don't have to stress yourself hoping to lose fat. Just watch any vegan video on Youtube, those people are lean and they are having breakfast [18].

If you are already tried some -restricted- diets or you came in with high stress levels and poor eating habits, you better avoid those fasting protocols and start having breakfast, in order to reduce your stress levels. If you have an elevated cortisol curve, skipping meals and abnormal eating patterns may increase the experience of stress.

According to a study [32], the increased meal frequency maybe is better option than eating just 2 meals per day.

Some tips

If you want to lose weight, improve your metabolism and your overall health, you have to choose real food and avoid anything processed. Is the plastic food that made you fat in the first place and not the breakfast.

Have only three meals per day and nothing else in the middle (or maybe a healthy snack, like a banana), can keep your insulin levels low and help you lose fat [19], while inducing important cellular repair processes, such as removing waste material from cells ([20]. Always have some starch with your meals, to keep cortisol levels low and boost testosterone [21].

For a healthy breakfast, there are many sites to get some ideas [22]. Avoid having meat for breakfast (especially processed meat products like bacon), as it has been linked to cancer [23], high blood pressure [24], heart disease [25], diabetes [26], stroke [27], dementia [28], obesity [29, 30] and so many other diseases [31].

Keep in mind that is the bad food choices that make us sick [33]. Take a look on Tsimané's diet and how they are keeping healthy [34].