I started the BSD 10 days ago. Well, I have to admit that I didn’t stick to 800 cals but did stick to the Mediterranean eating. I haven’t lost any weight which was a bit of a blow but I acknowledge that I’ll just have to get tough with myself and stick to 800 calories. The main problem I have though is that I feel exhausted. I have absolutely no energy and my head feels fuzzy all the time. I’m so lethargic. What’s causing this and will it go? If it doesn’t I’m not going to be able to stick to Mediterranean eating let alone 800 calories!

Hi Mursilis, and welcome to the forums.
I’m not sure what changes shifting to BSD style food has made to your diet, but in any case, a significant change in diet will all on it’s own cause a certain amount of stress, thereby increasing your protein requirement at least temporarily. Increased exercise also increases protein requirement. Not eating enough gives the symptoms you describe.

There may be other things that cause/remedy it, but for me protein is key. I need around 75g a day, less than 70 and I will be next to useless the next day. I’m not saying you will need so much, just pointing out that (as it’s hard to get 75g a day and still be less than 800 cals) I am very familiar with such feelings.

Hi Ancient Weaver
I hadn’t really thought about the amount of protein I was eating – I was just filling my plate with veggies. Good tip. I’ll try increasing the amount of protein. Thank you!

If you haven’t been counting calories and carbs, you don’t really know what’s happening. It could be carb flu, when your body feels extremely debilitated from carb withdrawal, an achy, shaky, exhausted feeling that is similar to having the flu. On the other hand, just because you’re eating a lot of vegetables doesn’t mean your carb counts are all that low. Not all vegetables are created equal, carb-wise, and there are probably other elements in your diet that you haven’t calculated.

If you want to get serious about doing the Fast800, measure, weigh and calculate every single bite of food that enters your mouth. Use an online calculator or app like MyFitnessPal or Fat Secret to look up the components of your meals. That will tally up total calories, carbs, fats, protein, etc. without you having to do the math. I keep my carbs extremely low because I am insulin resistant. Other people here aim for around 50 grams a day. I currently have my macronutrients set up to 20 grams of carbs (10%), 53 grams of fat (60%) and 60 grams of protein (30%) a day.

Good luck!