HELP to understand how many cals I should eat a day

http://www.myfitnesspal.com/topics/show/654536-in-place-of-a-road-map-2-0-revised-7-2-12

I see that this is your second post with the same question. Take a look at the links in the roadmap - they will help you decide what your daily intake should be. If you are doing JM 30ds you are probably moderate active.

With only 7 lbs. to lose, you probably shouldn't try to lose it a lb. at the time. I'm assuming that's how you got 1200 as a goal. Do you eat back your exercise calories? If so, then 1200 may be ok, but it's very close to if not below your BMR, so I wouldn't go any lower. You are a little smaller than I was when I started losing and a little bigger than when I joined MFP.

Google BMR and go to a couple of sites to figure it--they are all a little different. Then use that as a minimum number for your calories. And if you exercise, be sure to eat your exercise calories back, or it will take you below BMR if you are too close (that's the "net" number on your home page in MFP). You might also want to switch up your exercise. As your body gets used to a workout, you burn fewer calories doing it because you are used to it. 1200 calories may be enough if you aren't burning a lot, but if you are, it may be too low.

I keep hearing different opinions about the calories I should eat daily.
I try my best to eat healthy and I dont count my calories stricktly but when i say to my husband "that has too many calories", he gets mad and say calories doesnt matter, you have to be careful with fat, carbs, etc...

MFP suggest I should eat about 1200 cal a day, others suggest 1200 cal is too low. Of course I know nothing about nutrition, food, etc but I'm trying to get informed.

So my question is How many calories should I eat a day?
I'm 5'3, 142 lb, I exercise 6 days a week (JM 30DS). My goal weight is 135lbs

No one here is really qualified to tell you. You have to decide for yourself or ask a doctor for help.

1200 can work for some short people, not usually tall people. It all depends on your RMR. Taller people have a higher RMR so 1200 would usually be too low for them, but everyone is different.

1200 is such a stupid number to get stuck on. What you need to eat for a deficit is relative to your RMR. Your RMR could be lower than the calorie calculators say. The only way to know for sure is to test out the amount of calories and if you don't lose over time then you probably need to notch down by 100 until you find what works.

If you plug in all your info (typically age, gender, height and weight) into one of those calculators what you get is the average metabolic rate of a group of people who share your age, sex, height and weight. What you DON’T get is YOUR EXACT calorie needs.

To tell everyone eat more is wrong.

To tell everyone to eat less is wrong.

To find the exact amount of calories for you to be in a sustainable calorie deficit is correct. Some people can handle a deeper calorie deficit than others. Some people have emotional eating disorders and it comes into play. Even a small deficit puts your body in a state of flux and everyone is different.

I was able to handle a pretty deep calorie deficit because I'm very disciplined and eat healthy (good fuel for the body so I can perform well at the gym) and I do not have emotional eating issues. I have a very low RMR so my doctor said I could go lower than 1200. Everyone is different, I got scientific proof for myself during my 60 lb weight loss journey from obese down to 10% body fat. My doctor checked my hormone levels throughout the process. I have a low RMR, am short, older, and had to eat under 1200 calories to lose the 60 lbs. The DXA scan showed that I did not go into starvation mode or lose lean body mass. In fact in the end it shows I have higher lean body mass than most females my height. I am 5'1" and my lean body mass is 104 lbs. That is still pretty tiny because I'm petite, but it's high for my height and gender. Also the technician said my bone density is that of a super fit 30 year old and I'm almost 52. If that is not scientific proof that lifting weights keeps you younger I don't know what else is.

Too many changes at once can be hard on some people. I've always eaten healthy so it easy for me to simply eat less. Eating at a calorie deficit is hard on people; even a small deficit puts your body in a state of flux with hormones and such. Everyone is different. Some people can handle a deeper calorie deficit than others, this is not right or wrong, it just is. Stress in your life affects your hunger hormones; lack of sleep, fatigue, job stress, family stress, financial stress, etc. Add in emotional eating issues and it gets even more complicated. Most people can only handle so much change/stress at once, they try to do too much and fail. Sometimes it might be a better strategy to eat at maintenance and make some small changes first, it really depends on how much stress you are taking in at the moment.

Also the closer you get to your goal the less success you will have at eating at too low of a calorie deficit, here is why:

The Theory of Fat Availability:
•There is a set amount of fat that can be released from a fat cell.
•The more fat you have, the more fat can be used as a fuel when dieting.
•The less fat you have, the less fat can be used as a fuel when dieting.
•Towards the end of a transformation, when body fat is extremely low you
may not have enough fat to handle a large caloric deficit anymore.

At the extreme low end, when your body fat cannot ‘keep up’ with the energy deficit
you've imposed on your body, the energy MUST come from SOMEWHERE. This is
when you are at risk of losing lean body mass during dieting (commonly referred to
as ‘starvation mode’). This happens at extremely low levels of body fat, under 6% in
men and 12% in women [Friedl K.E. J Appl Phsiol, 1994].

-Brad Pilon and John Barban (from The Reverse Taper Diet in The Adonis Index and Venus Index manuals)

Also the closer you get to your goal the SLOWER progress will be, partly because you can't eat at a deep deficit anymore.

Your body loses weight in chunks, not linear. I have found that you can do everything right and your weight loss seems to plateau but if you are patient and keep exercising and eating at a deficit (however slight) you will lose it, it will suddenly "whoosh". There are so many variables for the scale; water retention, digestion, hormones, allergies, sodium, carbs, water intake, DOMS, inflammation, the list goes on. People mistakenly think they lose or gain weight when they eat more or less because of these fluctuations.

Losing weight requires tremendous patience. You will not lose it when you want it or where you want it. The body does its thing. Some apparent plateaus can last a month or so. You cannot make it happen faster. You must focus on two things; calories and exercise. Nothing else matters. Scales and metrics don't matter. The day in and day out grind of exercise and calories are all that matters. It is not very exciting until things fall into place. You get your victories and you ride one victory to the next.

The scale is a trend tool. The scale is good but put it away and only check once a week and only use it as a trend tool. It will fluctuate, it does not matter. Take front side and back progress pictures at least once a month. You will see differences that the metrics won't tell you and it's that little bit of NSV that will keep you going until the next victory.

To find the exact calories needed for YOU to be in a healthy sustainable calorie deficit is the right answer. Start with what MFP recommends, Wait, if you need to adjust by 100 do it, wait, adjust, wait, adjust, wait. The tortoise wins this race.

CaliforniaGirl said it all succinctly. It's just like clothing. What will fit you may not fit the next person who comes along. There are so many variables. Do what CaliforniaGirl suggested at the end of her post. Make it a long term lifestyle work in progress and keep at it til you are where you want to be. Good luck hun.