The “REAL” Science Behind Intermittent Fasting (IF) for Bariatric Patients

If you have tried Intermittent Fasting (IF) and were quick to give it up because you weren’t satisfied with the results, there’s a good chance it wasn’t being done quite right. Or, you may have seen substantial results quickly but then hit an intermittent fasting weight loss stall, leaving you stumped. 

In general, any weight loss (no matter the diet approach) will eventually lead to your body adjusting and getting used to the new weight, leading to a stall. On any weight loss plan (bariatric included), after you body has lost significant amount of weight (around 5 to 10 percent of total body weight) it isn’t unusual to experience slowed weight loss or a stall for a few weeks as the body resets. 

What do you do when you are at a stall while Intermittent Fasting?

Its totally understandable if you are feeling frustrated if IF is not working for you as a part of your weight loss plan, especially when so many people have made praises about it. If your weight loss doesn’t continue after the first few weeks, there could be other reasons it’s stalled. 

But don’t give up all hope just yet. There are steps you can take to break out of this stall. Here’s what might be hold up your weight loss and what to do about it to get back on track. 

  1. You’ve gotten too lax about tracking calories during your eating window.

One of the reasons IF works is that it leads to calorie restriction when you are eating only during set times. If you are eating too many calories during non-fasting times, even the calorie deficit experienced during the fast won’t be enough to offset overdoing it on the calories later. 

The Fix: Keep a food journal for one week to determine if you are increasing your calorie intake significantly during non-fasting times, making it easier to pinpoint where you may be falling short. 

2. You’re not getting enough exercise.

You’ve heard it a million times before: in order to see weight loss results, you need to focus on diet and exercise. 

IF, like any weight loss strategy requires an energy deficit to promote fat loss. If you are eating fewer calories but also moving less, you won’t have the same energy deficit as if you were moving more and eating less. 

The Fix: If you’ve stopped moving or started reducing your workouts, try to correct this by wearing a fitness tracker. Don’t overwhelm yourself with a big goal like running an marathon; instead, give yourself small step goals (a half-hour daily walk, for example) to reach to boost overall movement. Don’t forget to incorporate strength training into your workouts and overall IF plan to fight against muscle loss. 

And if you’re feeling too tired or drained by your IF plan to move more, consider trying a different diet or a different IF schedule that might better suit your energy needs so you don’t feel fatigued. 

3. You aren’t eating the right types of foods. 


Simple sugars digest rapidly, leading to very little energy being used in the digestive process, and a quick, but not long-lasting spike in energy. So don’t expect to feel great and achieve the same results if you opt for a doughnut over a protein-packed smoothie for breakfast, just because they may have close to the same number of calories. 

The Fix: Foods that are rich in fiber and protein can require as much as 30 percent of their total calories to be used up during the digestive process. So if you’re weight loss has stalled, look at your diet as a whole. There may be areas in which you started off on point and have gotten lax about nutrition. 

Questions to ask yourself include: 

  1. Are you eating 30 grams or more of fiber per day?
  2. Are you taking in 20 to 30 percent of total calories from protein?
  3. Are you limiting simple sugars to less than 10 percent of total calories?

If you answer to any of these questions is no, make adjustments to your macronutrients to jump start the weight loss process. 

4. You’re consuming too many calories at the end of your daily window.

Its especially key to follow the same concept that breakfast is the most important meal of the day and should be larger in volume compared to lunch and dinner. This matches our hormone patterns of cortisol and blood sugar balance, which should be highest in the morning and decreases throughout the day into the evening. 

The Fix: Consider eating larger meals earlier in the IF period of the day and taper off to smaller portions later on. 

5. You aren’t sleeping well.

Sleep can have direct impact on body weight through its impact on appetite, basal metabolism, hormone regulation, and energy levels. So, if you’ve been sleeping less or are regularly dealing with interrupted sleep compared to when you started your fasting diet, this can be holding you back from achieving your weight loss progress. 

The Fix: To improve sleep quality, set a structured bed time and wake-up routine, going to bed and getting up at the same time every day. Put all screens away as soon as you hit those sheets – instead, try focusing on reducing stress levels by opting for more calming activities, like reading a book or doing a quick meditation session. 

6. Your hormone levels may be out of whack. 

This one is difficult to determine on your own without help of a medical professional. What we do know is that health needs can vary widely by individual, which is why IF simply may not produce the same results for everyone. 

Following the IF patter means we are eating according to our metabolism which is highest in the morning and tapers off throughout the day. Some people eat too much of the wrong foods closer to bedtime, disrupts the hormone system and sets off a cascade of insulin imbalances. 

The Fix: First, talk to your MD. But in general, the best strategy to prevent a slowing in metabolism with any weight loss plan is to prevent excessively low calorie intake (under 1,200 to 1,500 per day, depending on age/size). At the end of the day, it’s always best to consult with a knowledge professional before starting a plan like IF, especially if you have any hormone concerns. 

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