Diet help!!

[alice1999]

I am new to exercising and dieting and would like someone to confirm whether what I am doing is a suitable way of weight loss. I've used calculators which suggest I eat 1400 a day. When I go to the gym about five times a week I roughly burn off 600 calories a day. 

1. Is it okay for me to eat below 1400? (1000-1100) because I read that you need to eat more or else your body turns to starvation mode? 

2. If I burn off 600 calories, am I meant to eat 600 calories extra so a total of 2000 a day?

[alice1999]

***I mean to say I burn off 600 at the gym 

[Dominique]

Calculators assume an average activity level. For instance, this one (my personal favorite) assumes 5 levels that range from "sedentary" to "extreme". If you’re wearing your Fitbit 24/7, Fitbit will try to estimate your energy expenditure based on your actual activity everyday. I would suggest you wear your Fitbit for a couple of weeks, just following your normal routine, and see how many calories you burn in average, taking into account days when you are working out and days when you aren’t. Keep in mind this is an estimate, and many people find it tends to be on the high side.

Once you have determined your average TDEE (total daily energy expenditure = "calories burned" each day), pick up a sensible/reasonable/sustainable/manageable deficit, for instance 500 calories, or 750 calories. Substract that amount from your TDEE and you will have the amount of food you can eat.

Here are a few safeguards you can check to make sure you are not losing too fast, or eating too little:

- see if the amount of food you will eat is higher than your BMR (calculators usually let you determine your BMR based on your personal data).

- see if the calculated deficit has you lose at less than 1% of your starting weight per week. A 500 calorie deficit implies a loss of 1 pound per week.

How you fare according to these criteria depends on your activity level (if you are very active, you can afford to have a higher deficit without eating below your BMR), and on your starting weight / size (if you are a petite woman, 2 pounds per week will likely be too much).

Btw, 600 calories per workout sounds like quite a lot. How long and how intense are your workouts? Weight loss is primarily about nutrition, but activity does play a role. However, it’s better to consider your overall activity (formal workouts + everything else you do besides working out) rather than just your formal workouts.

[gtg947h]

I'm not personally a fan of targeting one set number of calories a day. It's hard to really know which activity level category you fall into without having good measurements*, and at that point why not use those measurements instead of estimates? 

What worked better for me was using Fitbit's system of a targeted deficit and tracking of calories burned.  I started by wearing my Fitbit 24/7 (except charging), diligently tracking food, and daily weighing at the same time/conditions (e.g., immediately after waking up and relieving myself but before eating or drinking anything) for a couple of weeks. I pulled the reports, calculated my total intake and calorie burns, and found my trendline weight change over that period.  I discovered that, on average, Fitbit was either calculating me burning about 150 calories more than I actually was, or I was missing 150 calories when logging.  But more importantly I found that the calorie burn number was reasonably accurate with a known error range.

Once I knew that I could better target a deficit.  I picked 1000, since (especially when I started) my daily burn was 3500-4000 or more.  Often I even finished well under that target and had plenty of room left.  As I lost weight and my metabolism slowed accordingly, I changed the deficit to 750. 

Now I've hit my target and I have a fake target weight entered with a deficit goal of 250 to account for that daily error (there's no other way to do that).  That's worked well since January and I've basically maintained my weight within a pound or two (vacations and trips to Mom & Dad's house haven't helped there...). 

This system worked for me because I'm motivated by food, I like to eat, and knowing what I've burned meant I could go and exercise more or otherwise be more active and "earn" extra food, dessert, etc.  It motivated me to work out more, so I got the benefits of good vigorous exercise and I got to eat more.  It was a win-win.

I know, and have the data to show it, that my "multiplier" puts me near the extremely active category with about 3400 cal/day over the past month.  My BMR is supposedly 1840; thus a multiplier of about 1.85.  If someone didn't see what I was doing, and if I didn't know my numbers, I'd probably pick the "moderately active" category with a 1.55 multiplier.  That would be well under my actual numbers.