Is a protein-sparing modified fast appropriate for people with gallbladder removal? Have you had that kind of patient experience and can you please share? In your experience, does it work for weight loss without adding physical activity into a person’s lifestyle? What contraindications of this type of diet have, if any, and in what situations do you recommend it to patients, and for how long do you recommend using it?

Now as far as what the PSMF is, it’s really designed to be a very temporary diet which should help kick start weight loss in people who are really in that obese category. I would not be using this with a client who just has maybe like 20 or 30 pounds to lose. We would be looking at this in someone who is in that obese or morbidly obese BMI category and only using it for a short period of time. Typically, a protein-sparing modified fast is very low in calories, usually under 1,000 a day, because the weight of the modified fast is to basically be mimicking fasting. Fasting would be not eating anything. The protein-sparing part of the equation is including lean proteins in that under 1,000-calorie intake, so you really keep fat and carbs as low as possible. You might have some nonstarchy veggies there and maybe take some supplements like vitamins, minerals, and salt—that kind of thing—to make sure that they’re not getting nutrient and electrolyte deficiencies to an extreme level. Really, the majority of the food that would be taken in on a protein-sparing modified fast would be lean protein. In the fast, patients would be going into ketosis, so you want to make sure that any person who is not an appropriate candidate for a ketogenic diet is probably not a good candidate for protein-sparing modified fast, and this fast is really not supposed to last very long. It’s something that, first of all, you want to make sure that the person is tolerating it, and some people will tolerate them better than others. Someone with type 2 diabetes will probably not tolerate about the same as someone who has normal blood sugar control.

As far as the gallbladder question is concerned, I would say, I mean, this is something you want to be really careful about, and honestly, if it was my patient, I would not feel comfortable doing that kind of fast with someone who had had significant surgery or was dealing with any sort of uncontrolled diabetes or anything like that. This is kind of one of those situations where you have to decide what you’re comfortable with as a clinician, but if you were going to do it for someone with a gallbladder removal, I would think that they should be able to tolerate it simply because with gallbladder removal, normally the issue that you’re going to see is fat malabsorption in a high-fat diet. Since the protein-sparing modified fast is a very low-fat diet, you don’t really need to have a highly functioning gallbladder to deal with that diet. It’s going to be different than the typical ketogenic diet that’s very high and fat since there’s no dietary fat coming in or very little dietary fat coming into need to digest. I have not had that kind of patient experience. Like I said, I don’t work with morbidly obese clients who need to lose weight, so I don’t have the opportunity to use that kind of fast. I have had internship experience working with people who have gone through bariatric surgery, so that could technically be considered a fast because once somebody goes through bariatric surgery, they’re on a liquid diet for at least a couple of weeks after that surgery, so they’re not eating solid food. They’re essentially fasting for the most part with a little bit of protein coming in. In that situation, I do think we’ve had some clients who did not have a gallbladder who went through that surgery, but it is something that you want to be monitoring very carefully. You want to make sure that the person is getting bloodwork done and making sure that they’re not having any issues with electrolyte imbalance, dehydration, or anything like that.

As far as the contraindications for this diet, like I said, if somebody has got severe type 2 diabetes, you might want to be careful about going straight into protein-sparing modified fast. I would also say children and pregnant women definitely would not be good candidates for this diet. Anyone who has had an eating disorder, a history of an eating disorder, or an active eating disorder definitely would not be a good candidate for this diet. Really, I would say the only real candidates for this diet would be someone who is obese who has tried losing weight using a normal Paleo approach, maybe a low-carb or ketogenic approach and was not successful and that they have at least 50 pounds to lose because if somebody doesn’t have at least 50 pounds to lose, going that low in calories is really not very safe. I feel like it’s kind of one of those diets that’s a last resort type of diet for someone who really has struggled to lose weight. That’s my opinion.

You know, obviously, there might be some people who feel like it is safe to do for other situations. I would be careful in an elderly population since older adults tend to struggle to get enough calories and protein anyway, and they have very little muscle mass to spare, so with the protein-sparing modified fast, you’re trying to avoid muscle loss, but you’re still going to have muscle loss. You can’t avoid it 100 percent, so with the elderly, it’s something that losing muscle at that age is not helpful, so you may want to reconsider if that’s appropriate for them.

For osteoporosis, a short-term fast shouldn’t be that big of a deal, but certainly, you wouldn’t want to be doing a long-term fasting type of situation where they’re getting very low-calorie intake.

Hypothyroidism, again, if it’s a short-term couple of weeks fast, that might be okay, but a long-term low-calorie diet can exacerbate hypothyroidism.

IBS might be alright just because fasting can be a good way to reset the gut flora. You just, again, don’t want to go too long because if you only are eating small amounts of protein for a long period of time, you’re not going to be feeding your beneficial flora and your gut very well, and hypothetically, that could cause dysbiosis in someone, which then can either cause or exacerbate IBS symptoms.

Like I said, this is kind of a last resort type of diet for someone who’s obese who has not done well doing a standard Paleo reset or even a keto diet, if they don’t tolerate or find success with those diets.

Hopefully that helps. Like I said, I don’t do this diet with my clients, so I don’t have a ton of experience to share. This might be a good question to ask the Facebook group of other clinicians to see if anyone else works with this approach regularly and has any feedback for you about what to pay attention to what to, what to look for as far as ruling out someone’s appropriateness.