Hi, I’m new to this but wondered if anyone had experience of being a low BMI and needing to get blood sugar down. I’m trying fast 800 now after my gp mentioned it.
Since April i went from 61kg to 52 kg, lost it pretty quickly doing practically keto (unknowingly, I was doing the first bit of the fast800 method). So my BS test went from 43 to 41 between April and July: all fine I thought. Well yes but 41 is still pretty high so I’m trying to get it down more by trying Fast800 techniques like TRE and 5:2. But I keep losing weight – currently BMI 19 and going down this week since starting it.
Wondering if anyone else has had this too and whether it does eventually settle? I am worried about eating more calories but also don’t want other problems. I’m active, 46, family history of type 1 and own history of gestational diabetes.

Hello Ihatepolitics. Welcome to the site. I noted you said on your profile that you are not underweight but think you mean you are not overweight. The only answer I can give to your problem is to increase your calories but keep low carb for the blood sugar issues. You can do this by including more fats in your diet and can luckily enjoy things most of us here have to eat in moderation. They are things that are still good for you and low carb like full fat cheese, plenty of nuts, avocados, oil in cooking, olive oil on salads, hard boiled eggs for snacks. If you eat this type of food and aim for around 1200 calories (or more if you still lose weight) you can maintain your current weight and help with your BG numbers.

Thank you, that’s helpful. So with fast800 it’s about having two days of 800 Cals to clear out the sugar, if I understand it right. And the TRE is about only eating in a certain window to clear out the sugar. So I’m not sure when I should be eating these extra things if I’m doing 5:2 and fast800… I am getting very confused and it’s making my brain hurt… I suppose I eat in the window but eat more nuts etc like you say, But won’t that affect sugar levels too as my body processes more all at once?

Ihatepolitics, I am not sure about your issue with BG as I dont think you are diabetic. Can you say if you are as it would influence the advice given.

You are confusing 2 diet, the Fast800 is an 800 cal per day (not 2 days on and 5 off – that is the 5;2). I think the Fast800 allows a few more carbs than the original Blood Sugar Diet (BSD) as that is specifically for people with blood sugar / diabetes issues. The 5:2 is more like sticking with 800 calories for 5 days and then having 2 days when you can increase to about 1200. I only do the BSD so not 100% sure on the number for the others. If you want to eat cheese or nuts or other fat dense foods (only good fats) then just incorporate them into your daily routines. For example, 2 eggs scrambled with creme fraiche and some cheddar cheese, lunch of Ploughmans includes cheese and walnuts – the calories are kept low but if you had 60g cheese instead of 40g you would be adding around 100 cals but zero carbs as cheese has no carbs. So you have now gone from 800 cals per day to 900 and I am sure you can find another 100 cals somewhere – maybe an afternoon snack. I am not sure what the problem is – you dont want to lose weight but you want to keep carbs low – just eat more very low or no carb foods.