Basal Metabolic Rate and Calories

BMR calculators may be way off. As you eat less, efficiency can increase through recycling (see calorie restriction below). If you don't trust your body (and therefore your appetite) to get you what you need, then Fast-5 probably won't work for you because you'll continually be over-thinking everything. The human body didn't need BMR calculators to survive very harsh conditions the past 100,000 years. It doesn't need one now - it has one built in that is excellent. It's the same system that works for animals including pets. How often do they eat?

As for your health, you have to define health to decide what is best for it. If health is maintaining your performance at the highest level for the longest number of years possible, the only things known to do that are modest exercise and calorie restriction, and the latter has only been demonstrated in animals (including monkeys). Calorie restriction is running on fewer calories, not more, and may manifest its benefits by triggering recycling that helps cells clean up.

Fast-5 encourages people to trust their appetite, which will work well if it has breaks between eating that are long enough for it to figure out how much fuel is stored and adjust itself accordingly. If you exercise more, appetite will go up. Exercise less, it goes down. It's a great system.

I feel the same way sometimes. I really only eat once during my window from 5-10. After I eat I am usually full. Sometimes I can't finish my plate. Some days I am able to and even have a bit more. I also don't want to starve myself but not hitting your calorie number every single day is okay for the most part. I ate 1350 calories yesterday but there was a day earlier in the week I only got down about 700 calories. I usually eat lower carb but I also enjoy my food and try not to get all freaked out about how much I am eating. I've been doing the Fast 5 for about 11 days and I am down 9.2 lbs. If it works out that I don't eat the same calories each day I think that's better. I like to keep my body guessing how many calories it's going to get. I used to do the Alternate Day diet by Dr. Johnson. I really like Fast 5 better. I can actually live on this so easily. BUT Dr. Johnson's book is a good reference to show you that you don't really need to eat the same calories daily. Good luck! I'm pretty happy with these results so far. How are your results going?