Before changing the way you eat and altering your diet in any significant way, please speak with a health professional to make sure it’s the best decision for you.

So your friend lost 15 pounds, and your dad can’t stop raving about the blood sugar-regulating merits of intermittent fasting. You’ve reviewed the how-to manual (here) and carved out a routine, but for some reason, you haven’t seen any benefits. We’ve compiled some of the biggest mistakes you’re likely making in your intermittent fasting regimen.

1. You’re jumping into intermittent fasting too fast.

The biggest reason most diets fail is because they’re such an extreme departure from our normal, natural way of eating that they often feel impossible to maintain. Just a thought, but if you’re new to IF and are accustomed to eating every two hours on the hour, maybe don’t throw yourself into a hard-core 24-hour-fast from hell. If you’re adamant about the concept of fasting, start with a beginners 12/12 method where you’re fasting for 12 hours per day and eating within the 12-hour window. That’s probably pretty close to what you’re used to doing anyway, and who knows, it might be the only (if even that) sustainable way to follow along.

2. You’re choosing the wrong plan for your lifestyle.

Again, don’t set yourself up for misery by signing up for something you know is going to cramp your style. If you’re a night owl, don’t plan to start your fast at 6 p.m. If you’re a daily gym-goer who Instagrams their WOD every morning and aren’t willing to sacrifice your daily Spin, don’t choose a plan that severely restricts calories a few days a week. You gotta do you if you want any habit to stick.

3. You’re eating too much during the eating window.

This one is the most common trap I would expect to see people fall into with IF. If you’ve chosen a particularly restrictive regimen that’s left you hangry AF for hours of the day, the moment the clock says “it’s time to eat,” you’re likely to go a wee bit overboard. Research suggests restrictive diets often don’t work because we tend to become so emotionally (and physically) starved that when we do allow ourselves to eat, we go hog wild and overeat in a fit of deprivation. Any diet that has you preoccupied with your next meal is a recipe for a binge so make sure you’re not allowing yourself to feel unnecessarily hungry for long periods of time.

4. You’re not eating enough during the eating window.

Yep, not eating enough is also legit cause of weight gain, and I’ll tell you why. In addition to setting yourself up for a rebound similar to what we discussed with the last common IF mistake, not eating enough cannibalizes your muscle mass, causing your metabolism to slow. Without that metabolic muscle mass, you may be sabotaging your ability to maintain (never mind to lose) fat in the future. The challenge with IF is that because you’re eating according to some arbitrary temporal rules, rather than listening to your body’s innate cues, it’s really difficult to know your true needs. If you’re adamant about doing the diet, be sure to speak to a registered dietitian to help you assess and meet your nutrient needs safely.

5. You’re ignoring the what in favor of the when.

IF is a time-centered diet, and most of the “plans” don’t give any explicit rules about the types of food to eat during your “eating window.” But that’s not an excuse to subsist on a diet of French fries, milkshakes, and beer. Fasting isn’t magic. In addition to some small metabolic advantages, its primary impact on weight loss (if it even has one) is largely based on the fact that you’re limiting your number of eating hours and therefore reducing opportunities for calorie consumption.

Unfortunately, that effect can be quickly undone if you choose the wrong kinds of foods. Shift your perspective from the idea of treating yourself during your limiting “feasting” hours to getting in the most nutrient-dense, nourishing foods during those times. We recommend ensuring every meal or snack has a combination of satiating fiber, protein, and good fats to help carry you through your fasting phase.

6. You’re not drinking enough.

Your intermittent fasting regimen might have you refraining from food, but water should always be nearby, especially since you’re missing out on the hydration you often get from foods like fruits and veggies. Dehydration can lead to muscle cramps, headaches, and exacerbate hunger pangs, so always make sure you’re sipping H2O between (and during) feasts.

Followed all the rules and still struggling? It’s not you; it’s likely the diet. Research suggests that intermittent fasting has a 31 percent dropout rate, while research on diets in general suggests that as much as 95 percent of diets fail. Try to focus more on what your body tells you, rather than what the clock says, and you’re much more likely to get the nutrition your body needs.