I’ve noticed a lot of questions about calculating your RDI, and after some experimentation and discussion with my doctor, I’ve arrived at a formula that helped me better adjust my calories to achieve my weight-loss goals. I wanted to share it with you.
DISCLAIMER: This is not a quick answer. It takes experimentation and testing! But if you’re counting calories anyway, you might like this feedback, and I found the FatSecret app to be enormously helpful.
I started by weighing myself at a regular time each day – when I first woke up. I am trying to be as consistent as possible to get more accurate feedback. Also, I’m trying to “ignore” that number as a sign of “real progress” because I know my weight fluctuates. (I’m just gathering data here.)
I started at 222 lbs, and FatSecret calculated my RDI to lose 1 pound per week based on my normal (fairly sedentary) activity at 1,800 kcal/day. This implies it thought I was burning about 2,300kcal/day doing normal activities, since 3,500 calories = 1 pound of body weight, and it was recommending I create a calorie deficit of 500 kcal/day = 3,500 kcal/week.
I set up my activity counter for a “typical day” – that is 8 hours sleeping, 7.5 hours “resting,” 30 minutes of housework and 8 hours of desk work. Here, FatSecret estimated I was burning 2,770 kcal/day. So one could conclude that if I stuck to my sedentary lifestyle (I work from home at a desk) and ate 1,800 kcal/day, I would actually lose 2 pounds per week (~1,000 kcal/day deficit, for a total of 7,000kcal/week).
Not so fast. That did NOT work! In fact, every time I’ve done that, my weight has gone up.
I know that diet and exercise must go hand in hand, so I have committed to walking 3 miles per day at a brisk (3.5-3.8 MPH) pace. That usually pushes me over 3,000 kcal/day burned. I only log exercise that makes me sweat—housework (with two little kids, there’s a lot of picking up), walking on the treadmill or in my neighborhood, etc. I get in at least 18 miles per week, and I am also using 2-lb weights to tone my arms while on the treadmill.
I am counting every calorie as well. One FatSecret member logs all of her BLTs (bites, licks and tastes). A lick of frosting might have more calories that a whole cup of berries!
Now, after doing this for 35 days, I can look at my results. The app offers a nice summary of my monthly performance, so I’ll share my May results: Daily average calorie intake: 1,518 kcal
Daily average exercise: 3,052
Daily average calorie deficit: 1,534
Total May calorie deficit: 47,545, which should equal 13.6 pounds lost
Actual weight loss (May 1: 214.0; June 1: 207.7): 6.3 pounds
So what does this tell me? It says that I am on the right track, and losing 1.5 pounds per week, roughly a 711 kcal/day deficit. So my workouts and food are actually only that far apart, not the 1,534 kcal deficit FatSecret suggests.
When I first started FatSecret (and working out and eating right), I did the math and saw that I had lost 10 pounds for a 35,000 kcal deficit, but now that my weight loss has slowed a bit (no doubt from a slightly smaller body as well), I think doing this math really helps my accuracy in setting and achieving my goals and keeps me from getting frustrated when the scale refuses to budge. Now I know why!
That also tells me that if I want to keep losing weight at this pace (and I think 1-2 pounds per week is reasonable and healthy), I need to keep striving for a deficit of 1500 kcal (based on FatSecret’s tracker), not the 1000 kcal deficit I would get by remaining sedentary and eating 1,800kcal per day.
So that’s my plan. I also reviewed this with my doctor and she agreed that eating 1,500 kcal per day would be reasonable and healthy for me as an RDI.
What do I eat? Everything, including some sweets. My macronutrient ratio (which I calculated based on 20 days of food logging) is 20% fat, 23% protein and 56% carbohydrate, or 63 g fat, 71 g protein and 172 g carbs on average. I’m pushing to reduce carbs and fat and increase protein, but I’m pretty close to where I want to be. I often make a green smoothie for lunch (spinach+lime+frozen fruit+whey protein) and my go-to foods are turkey, Greek yogurt, berries, wheat toast with peanut butter and roasted vegetables.
Thanks, FatSecret buddies for all your love and support! I am confident I can reach my goal!
I am not losing weight. I am gaining health. Since April 24, 2012: