In part 1 of this article, I discussed micronutrient (vitamin/mineral) deficiencies that I commonly see when individuals follow a strict SIBO diet. In part 2, I will focus on macronutrient (calorie/carbohydrate) deficiencies.
Side note for the detail oriented: I included fiber in part 1 of this article, but it is actually a macronutrient.
I find that individuals following restrictive diets are more likely to notice the effects of macronutrient deficiencies before they notice micronutrient deficiencies. I also find that these deficiencies are rampant in the SIBO community, even among individuals being advised on diet by a healthcare practitioner. The issue is near and dear to my heart.
The initial stages of my healing journey were well before I studied nutrition. When I was prescribed Dr. Siebecker’s SIBO Specific Food Guide by my doctor, I received no guidance on how it should be implemented. I followed the diet strictly (with additional dangerous modifications- no fruit, autoimmune paleo (AIP), low sulfur, no sugar) for 5 months- fearing that I would ruin everything with one deviation from the protocol. During that time, my digestion finally started feeling normal for the first time ever, my acne cleared up, and I didn’t have 24/7 miserably itchy skin.
But, I was so focused on my digestion and “the protocol”, that I ignored the other signs my body was giving me. Big mistake. I lost 10 pounds, my thyroid showed signs of hypothyroidism and hyperthyroidism, I developed amenorrhea (no periods), fatigue made it hard to hold even a part-time job, I got six dental cavities despite eating no sugar whatsoever, and food was no longer exciting. None of these were issues that had ever occurred before following this restrictive diet.
What was going on? Well, I was experiencing a macronutrient deficiency. A lack of carbohydrates was to blame for my new signs and symptoms caused by trying to be a “good patient”. Typical “type A” behavior. But my practitioners didn’t realize that I was suffering from a carbohydrate deficiency.
When I was finally able to get the right supplements in place to support my digestion and overall health while strategically introducing certain carbohydrates, I felt amazing. My digestive symptoms stayed at bay, but I began to function more normally in society and began to enjoy food again. I regained the weight (that’s a good thing!), my thyroid levels normalized, and my menstrual cycles returned.
But the disastrous 5 months could have been prevented with skilled nutritional counseling.
The Food and Nutrition Board of the Institutes of Medicine (IOM) recommends that Americans consume 45-65% of their daily calories in the form of carbohydrates . For someone consuming a 2,000 calorie diet, that is 225-325 grams per day.
Those following the SIBO Specific Diet would have an exceptionally difficult time consuming that many carbohydrates in a day. Now, I am not saying you necessarily need that many carbs to be healthy. Many people (especially those who are not very active) feel okay or even better on lower carbohydrate diets. But I wouldn’t say that’s the norm.
Let’s look in more detail at what would be considered a “low” carb vs “very low” carb diet.
Low vs Very Low Carbohydrate
There is no generally agreed upon definition for what constitutes a low versus very low carbohydrate diet. But I have scoured through the research to bring you an idea.
- Low carbohydrate = 20-40% of total calories from carbs  (~100-200 g/day based on 2,000 calorie diet)
- Very low carbohydrate = 0-20% of total calories from carbs  (~0-100 g/day based on 2,000 calorie diet)
Typical SIBO Diet Carbohydrate Intake
One of the primary sources of carbohydrates for those on the SIBO Specific Diet is fruit. The others commonly recommended to individuals following this diet are white rice/potato (depending on what version of the diet is followed) and honey.
Let’s take a look at how many carbohydrates might be consumed in one day by someone on a SIBO Specific Diet:
- 1 medium banana = 29 grams of carboydrates
- 1 cup sliced strawberries = 13 grams of carbohydrates
- 1/2 cup cooked white rice = 23 grams of carbohydrates
- 1 small red potato = 27 grams of carbohydrates
We know that there are carbohydrates coming from the vegetables consumed too (carrots, squash, etc). For example, 1 medium carrot contains 6 grams of carbs. But this is minimal when compared to what’s coming from fruit, potatoes, rice, or honey because the FODMAP & SCD diets limit or exclude high carbohydrate vegetables.
That brings us to a total of around 100 grams of carbohydrates in one day on a SIBO diet that includes rice & potato. That’s right on the border of low and very low carbohydrate. For those on a SIBO diet who restrict fruit intake or who do not consume potatoes or grains, you are likely to be following a very low carbohydrate regimen.
Those who follow a low FODMAP diet that is NOT combined with SCD are likely much closer to the normal carbohydrate range. This is because of the decent amount of carbs that is coming from grains, corn, and sugar.
Dangers of Low Carbohydrate Diets
I understand the desire to want to restrict carbohydrates for symptom reduction, but I also want to make sure that others do not deal with the unnecessary onset of symptoms caused by restricting too severely.
If you are embarking on a low carbohydrate diet (especially very low carb) I would encourage you to keep an eye out for the following signs and symptoms cited in studies to be associated with low carb diets :
- Mood disturbances- anxiety, depression, anger
- Fatigue or weakness
- Poor physical exercise performance
- Less vigor and imagination
- Muscle cramps
- Skin rash
- Unintentional weight loss
- Decreased fecal short-chain fatty acids (SCFAs)
- Increased output of calcium in urine (risk factor for kidney stone formation)
- Decreased bone mass (risk factor for osteoporosis)
- Kidney dysfunction (from increased protein intake)
- Stunted growth in children
- Specifically, this occurred in children on ketogenic (low carb/high fat) diets for epilepsy
These symptoms can occur for a variety of reasons. When in the context of a diet that is too low carb for YOUR body, these symptoms can often be explained by one or more of the following: low blood sugar levels (glucose is the preferred source of fuel for the brain), low glycogen stores, stress on the adrenal glands, slowed thyroid function, or reduced serotonin levels (carbs play a role in the synthesis of this neurotransmitter).
There are three macronutrients that supply our calories- carbs, fats, and protein. And a fourth for some- alcohol. When we restrict any one of these macronutrients, without increasing one of the others, we are decreasing our total calorie intake.
We know that the SIBO Specific Diet intentionally restricts carbohydrates for symptom reduction. So what do we increase? Some may increase fat, some protein, but more likely an increase in both is needed to obtain adequate calories to feel satiated and maintain weight. But fat atop protein is not nearly as satisfying as fat atop carbs. Think a tablespoon of olive oil on your pork versus on your potato. Which sounds more appetizing to you?
I see many following SIBO diets who unintentionally consume less calories than needed for maintaining their health. This can happen for a variety of reasons:
- Not having the time or interest to cook
- Not being excited about food and therefore eating less
- Not realizing how much more they need to eat to make up for the decrease in carbohydrates
- Not having the time to eat such a large quantity of nutrient-dense, but calorie-poor foods
- Fasting between meals that reduces overall intake during the day
Remember, the goal is to starve the bacteria, NOT YOU! If you feel like you need help navigating your SIBO diet, please reach out- I am here to help.
 Manore MM. Exercise and the Institute of Medicine recommendations for nutrition. Curr Sports Med Rep. 2005;4(4):193-8.
 Frigolet M, et al. Low-Carbohydrate Diets: A Matter of Love or Hate? Ann Nutr Metab. 2011; 58:320-334.
Karen M. Roth says
I am pretty sure that I have SIBO but I am also on the IC Diet plus,my pain management specialist is wanting me to go on a gluten-free and anti-inflammatory diet and I’m also allergic to dairy and I am pre-diabetic. I have food allergies, too.
WHAT is left that is easy to fix in 2 minutes or less since I already have untreated Psoriatic Arthritis /Ankylosing Spondylitis, Osteoporosis and Osteoarthritis and Carpal Tunnel and Tendinitis?
I also do not have teeth and cannot get dentures yet, but will work on it as soon as I am able to.
Things that I can get on Food Stamps.
Thank you for your time.
That definitely sounds like a tricky situation! I am sorry you are dealing with so many health issues. The only thing that comes to mind is making smoothies. Hope that idea is helpful!
Riley, What are some ways to get more Carbs/Calories if diet is restricted due to SIBO? My husband has lost so much weight/muscle mass. I’m sure he’s not getting enough calories and nutrition. He use to be 165lbs, now he’s 135. Also, what was your typical meal plan like for a day when you were being treated for SIBO?…what did you eat? This diet is so restricted…I don’t know what to fix anymore and he’s bored with what he’s eating. Thank you for all the great info and sharing your experiences.
Thanks for reaching out! I regularly see the issues your husband is dealing with and have plans of creating low cost meal plans, guides, etc that could potentially be helpful. In order to answer your questions appropriately, there are a lot of things I feel like I need to ask you before providing advice. But one of the ideas that I often recommend when working with my clients is to add a smoothie during the day with lots of healthy fats. I often recommend specific foods to increase carbohydrate intake, but the specifics are based on the individual scenario/tolerance.
My husband (and I) has been on the SIBO diet for six weeks. His gastroenterologist was pleased with his progress (diarrhea finally stopped after four months) and said he can begin to introduce the forbidden foods. We are both so concerned about his experiencing a relapse and uncertain as to how to go about this. There are conflicting suggestions in terms of foods that are “acceptable”, such as potatoes. Which food do we start with? He is type 1 diabetic, so this lack of carbs has been very tricky and we hope to find some foods that will help in this regard but not feed the bacteria again. Thank you for your advice.
It is certainly common to feel a bit fearful introducing new foods after finding something that works! I usually tailor recommendations to each client based on their most troublesome foods in the past, what foods they most need to fill nutrient deficiencies, what they are craving, and other factors. There aren’t really blanket recommendations since everyone is so different. I usually stay away from gluten-containing grains for reintroductions. Some examples of foods I might trial with someone would be quinoa, sweet potatoes, rice, or certain fruits.
Can u help with diet veg I almost I donno what to eat
Hi, It’s very challenging to combine a SIBO diet with a vegetarian/vegan diet and get enough to eat. I’d highly suggest working with a nutritionist to determine a dietary approach that would be a better fit. I’m not accepting new clients at this time, but feel free to contact me via my contact page if you need a referral.
Omg so glad I found your post! This is exactly what happened to me. Now, Im not sure yet if I actually have SIBO but when I got into a more SIBO diet I didnt realise I lost so much muscle mass and weight that I got severe symptoms just by doing that. I went from 187 lbs to 154lbs. Today I eat alot more carbs to gain my weight back and muscle mass but its hard. I have no stomach pain but now I have alot of bowel gas. Im not sure if that is SIBO or the stomach not used to carbs. Any thoughts?
Hi Philip, I’m so glad you found this post helpful! Thanks for commenting! Your story is all too common- which is exactly why I wrote this post. Depending on what carbs you are eating, I have a few ideas for what could be causing the increase in gas. If you are eating higher FODMAP carbs (such as beans or large amounts of certain starchy veggies), there can sometimes be an adjustment period where the healthy gut bacteria haven’t been fed in a while so they produce gasses as their populations are restored. As long as there aren’t accompanying symptoms such as diarrhea, constipation, or super smelly gas, this usually isn’t a reason for concern and will likely dissipate with continued consumption. If it persists, than perhaps there is a little dysbiosis that could be addressed. If your carbs are coming more from simple carbs (sugar, white rice, white potatoes, tapioca starch, etc.) and those are causing gas, I would be more inclined to think that there is an overgrowth of yeast (such as candida) or that they are being consumed in excess (since a little candida in the gut is normal). I wish I had a more straightforward answer for you, but this stuff is complex! I hope that helps!
Thank you very much for your reply!
I found out today from my practitioner that I have SIBO (methane dominant). I’m just afraid that i will lose more weight when I get on his SIBO diet now. I going to supplement with herbs to see if it will help me. I’m definitely have a gut dysbiosis since I constantly getting gas bubbles and nausea.
Question – can I still get enough glucose and calories on a regular SIBO diet or should this be modified?
Thank you very much 🙂
It really depends which SIBO diet you are referring to and your own personal carbohydrate and calorie requirements. Also, how much time, skill, resources, and motivation you have to cook for yourself. It can definitely be challenging to get enough carbohydrates and calories on some SIBO diets. Less so with only low FODMAP and more so the greater the degree of restriction. Hope that answers your question!
Feel like Im suck between a rock and hard place now. I weigh 154lbs and I’m 6’5 tall, which gives me a BMI of 18.1 (underweight). I’ve got a protocol from my practitioner to do the SIBO diet and use Allimed, Oregano and berberine and fast 16 hours after 6pm.
I’m so afraid to lose more weight and not getting enough carbs and calories as you understand.
In your opinion, should I still incorporate some rice and see if that triggers my symptoms? Or are you free for a consultation?
Hi Philip, Hope you are doing well! My schedule is full and I am not available for consultations at this time. I would say it is best to follow the advice of your practitioner and if you feel they are not providing proper support, then seek out a new one. Unfortunately, I cannot offer personalized support without doing a full intake.
I’m on the SIBO diet by Dr. Allison Siebecker, and was wondering if the portion restrictions are per meal or per day total? I couldn’t find any information about this online and wanted to make sure I’m following it correctly. I also notice some of your recipes include white rice, but are grains and potatoes allowed on this diet?
Hi Clare, my understanding is that it’s per meal. The reason some of my recipes include white rice and potatoes and is that at one of the NUNM SIBO conferences, Dr. Siebecker mentioned that many people she worked with tolerated these foods. Additionally, the SIBO food guide is too low carb for many people (especially women), resulting in hormonal issues, fatigue, brain fog, etc. Adding white rice and potatoes helps supply more carbs. I do also want to mention that I highly recommend working with a nutritionist while following that dietary approach. It’s not an easy one to follow and can result in nutritional deficiencies if not done with care. I’m not accepting new clients at this time, but feel free to contact me via my contact page if you need a referral.