How to deal with the weakness and passing out

TLDR Doctor gave me an eating plan, says I need to get used to it, I feel like a dead body even on the days where I eat. On a dieticians recommendation I've started doing 3 on - 4 off fasting where I eat 2 meals a day @maintenance calories for 3 days, water fast for 3 days and then absolute zero intake fasting on the last day. 6 weeks ago I was 240 pounds at 23% BF, now I'm 225 and I'm looking to get down to 145-150 at 11% BF. Problem is, I don't have any energy to do anything. I've been doing it for 6 weeks now and my dietician tells me I will get over the hump and start getting energy back as people eat way more than they need to and my body is figuring out how to go back to its natural state and be more efficient. She wants me to start doing long distance walks and short distance runs at 8 weeks and I don't know how I'm supposed to do it.

Answer

Fourth or fifth in to ask: are you seeing a REGISTERED Dietitian (they’d have RD, RDN credentials after their name).

I have a dietetics degree and can tell you: this is not in the approved scope of the Academy of Nutrition and Dietetics. It’s very much outside of evidence based practice and would likely be considered a reportable offense (reportable to AND for violation of Code of Ethics, citing: Competency).

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Wow! This is pretty dramatic advice from a dietitian. On the one hand I’m happy you found a dietitian that believes in fasting, but on the other hand I’m dismayed that you found one who sounds a little draconian.

I’m leery of contradicting a professional, but if you feel like garbage it doesn’t sound like the diet will be tenable with the addition of exercise.

In your place I might pivot to a less ambitious plan and then ramp up. I’d probably try eating my TDEE minus 500 calories every day, eat in an 8 hour window, and add in walks. When you’re comfortable you can tweak one lever at a time: either add mileage to your walks, throw in a jog, shrink your eating window a little, or cut another 100 calories out.

Good luck!

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yeah this is outrageous!

omad or IF would have been a good place to start. slowly introduce your body to fasting before taking it to this level.

congrats on the results but… don’t endanger yourself like this.

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Interesting. I do a similar approach: fast for 3.8 days, then eat for 3.2 days. Repeat each week.

During the eating days I don’t worry too much about caloric intake, and am certainly in calorie surplus. I manage to squeeze in a couple of (fairly intense) weight training sessions in during the eating period. In addition, mental energy is quite good (why I follow this protocol). I was losing 2lb/week but that was too fast, so focused on eating more and am now a bit under 1lb/week.

One thought: I suspect I find the continued transitions between fasting/eating doable due to eating very low carb (well, carnivore) during my 3.2 days of eating. My body is pretty much always in fat burning mode. Continually cycling between a carb metabolism and fasting sounds brutal, and I suspect I’d be hangry and tired as well.

I’m also baffled by the recommendation for no water intake on the final day. Was there a justification given?