Yeah sorry Sam, I noticed you weren't on week 1 after I posted
For measurement locations, the best ones are as follows; neck, upper arm, chest, waist, hips, thigh and calf.
Basically if your body is burning more calories than it's consuming, you will lose weight.
You are only consuming 600 calories a day, well below what your body needs on a daily basis to maintain.
If you add in light exercise (break into a sweat) 1-3 days a week you would be looking at around an extra 200-300 calories a day that your body would need to burn each day.
Here is an example of the daily calories I need;
2160 (BMR) x 1.2 (little or no exercise) = 2592 daily calories (even if I stayed in bed all day)
2160 (BMR) x 1.375 (light exercise 1-3 days)= 2970 daily calories
So if I'm only consuming 600 calories yet my body needs 2970 each day (2370 more than I'm consuming), it's going to burn the fat stored instead through ketosis.
Does this help?