I am interested in Zone for athletic performance as well as fat loss. I've read Dr. Sears "The Zone: A revolutionary plan..." book. My question is regarding block requirements for a woman who CrossFits 3-4x per week and is training for a half marathon.

(Please don't judge my numbers... I have weight to lose... and am working on it)

I am currently 225lbs and my last hydro-static body fat calculation was 37% (I'm rounding that up to 40% since I gained about 8lbs over the holidays).

LBM - 135lbs,
Moderate activity = 94.5g protein = 13 blocks,
Active = 108g protein = 15 blocks,
Very active = 121.5g protein = 17 blocks

When I originally set up meal plans for Zone I set it up for 13 blocks (under the suggestion of a my coach). I also track my calories and noticed that I would be way under my calorie goal (set up by calorie deficit from TDEE). For example yesterday I did a lunch time run and CrossFit in the evening (total of 800 cal burned by HRM) and consumed a total (not net) of 1695 calories = 13 blocks which is below my BMR. I did get up about an hour after I went to bed because I was hungry (as in stomach growling hungry) and ate another 1 block snack.

What I'm concerned about is screwing up my metabolism because I am not eating enough for the amount of exercise I do.

Would you all suggest that I increase the number of blocks greater than 13 blocks? This just seems like A LOT!!

Thanks!

Hi Ruth,

Don't try to compare the number of calories you eat when following the Zone diet to the BMR recommendations. Those recommendations are usually based on in individual who burns carbphydrate to produce ATP (Adenosine Triphosphate, the primary fuel used by cells to generate the biochemical reactions essential for life; the fuel for every muscle contraction that takes place). With the Zone diet the body burns fat to produce its ATP. More ATP is produced from one calorie of fat than from one calorie of carbohydrate. Following the Zone diet translates to fewer calories being consumed to produce more ATP as compared to following a typical higher carbohydrate diet.

With the Zone diet, you eat the amount of lean protein necessary to support your current muscle mass at your current physical activity level, and then compliment that with an appropriate amount low density carbohydrate and monounsaturated fat in order to maintain a low insulin level. This allows you to have excellent mental focus and clarity, to keep cellular inflammation to a minimum and to produce plenty of energy.

To apply all of this to your needs, I think you might be underestimating your activity level. CrossFit is primarily an anaerobic activity, comparable to strength training for Zone protein requirement calculations. Though you have not delved into the specifics of your CrossFit and half marathon training, I'd suggest you use Very Active, or, at the least Active, rather than Moderate, simply for the reasons that 3-4 days of CrossFit is akin to 3-4 strength training sessions weekly plus you are adding the distance running training. As you mentioned, Very Active, assuming 135lb LBM, gives you a daily protein recommendation of 122 g, which falls between 17 and 18 blocks daily. Try 17 blocks daily. Choose vegetables for most of you carbohydrate. Apply the 4 hour hunger test to further fine-tune to eliminate hunger.

Please keep us updated here. I'll be happy to help!