Target weight depends on height, age, bone structure, level of activity, climate, as well as on more cultural and social factors. Here are some suggestions, edited somewhat from April's blog entry on 26 April 2007.
If you are trying to lose weight , you shouldn't lose more than 1 pound a month if you're starting lean, no more than 2 pounds a week if you're starting overweight.
Feeling hungry may not be a good indicator: many people, especially those who are overweight, will tell you that they are not hungry when in weight loss, but they are eating so few calories that they are losing weight too fast. When people first discover the filling deliciousness of low calorie, high nutrient veggies, they sometimes eat too few calories yet still feel full. At this point, add more calorie dense foods, like nuts and some olive oil, to your diet to slow weight loss.
As to where you end up (because obviously, you don't lose weight forever -- you find a point where you're comfortable and then you stay there): there are many different answers, and I think it's a very individual decision.
You should be very conscious about your general health : one way to track this is to work with your doctor to monitor your blood work to make sure that all your health indicators are improving.
Make sure that you're getting adequate nutrition : one way is to track what you are eating. COM incorporates the USDA Dietary Reference Intakes as the default recomendations, although you can reset your targets. The method won't work if you don't get the nutrition you need, and people who think they're eating a healthy diet are usually low in some essential vitamins and minerals. Calcium is often a concern for women. It takes some work to get the vitamins and minerals you need, and most folks who eat ad lib are somewhat malnourished, so when you talk about decreasing your calories, you have to work even harder to get appropriate nutrition. That's why we weigh and measure stuff... so we actually know what we're eating. You don't know how much calcium you've had if you have only a vague idea how much yogurt you ate. You don't know how much vitamin A you had if you had a random amount of kale. If you've got a diet worked out where between breakfast and lunch and your megamuffin snack you get all the RDAs, then on a day when you have dinner out you can worry a lot less, since you know you've already got all your nutrients in the bag.
April said "I know that I hit the limit of my social and work life far before I really find hunger to be an issue. Between going out for work and social events and still getting the nutrients I need in my quotidian diet, I have never gotten much below 1300 calories a day, and these days with exercise I'm more in the neighborhood of 1500. On days when I take Pilates I eat an extra 300 calories, on days when I don't I hit 1300 ish pretty consistently, though lately with all my travel and going out, I've been going lower on quotidian days so that I can ease up a bit when I'm on the road with my good food eating fine wine swilling buddies. It's a tragedy to turn down a second glass of a really good Malbec, so I make compromises."
"MR chooses 115lbs as a somewhat arbitrary marker, but it does seem to be the weight at which he's very comfortable, maintains physical strength, and yet keeps his calories as low as he can while maintaining the things in life that are important to him. He doesn't feel much hunger, though right before meals he's definitely ready to eat. When he finishes a meal, he's satisfied.
A lot of women keep their calories above the point where they would have amenorrhea. Of course for the post-menopausal that's not an option. I haven't hit amenorrhea, so that's not a marker for me.
If one is carefully monitoring one's health (we do our blood tests every six months or so) and getting adequate nutrition, then it's all about what you consider quality of life. I have a friend who has to eat enough to spend about three hours a day surfing. For me, surfing is not a concern, but for him, life would not be worth living without the sport.
Some people find that they take their calories quite low, then increase them. This could be based on any number of factors, from social situations changing to wanting to take part in more exercise or sport. I increased my calories when I started exercising more seriously, because I feel that the health benefits and psychological stress reduction benefits of my exercise routine are worth the extra calories. Yet I'm not an athelete by any means: I take Pilates twice a week, do some weight lifting, and do 20 - 40 minutes treadmill at between 4 - 5 mph. Nothing crazy, but enough to burn some calories and make some muscle. I just love the way I feel when I'm exercising regularly and well, especially in combination with consistent low calories and high nutrition.
So to sum up: if your bloodtests and your vital signs are all excellent, and your nutrition is optimal (as monitored on software, not based on your estimation of what is "healthy") and you're getting enough exercise to maintain cardio health and bone health, then how low you take your calories is based on a set of factors that only you can determine. What are your priorities?
Because we are not rodents in a cage, we can't control every aspect of our lives. We have many choices, and we have to take responsibility for the choices we make. I encourage all to do their own research and decide what works for them, always in consultation with their doctor. If you'd like some articles that you can provide to your doctor about CR, I can send them to you. There is no magic number of calories, and there is no one size fits all.
As I've said many times, you eats your veggies, you takes your chances. I believe in living life to the fullest every day, for as many days as I possibly can."