I'm having stir-fried bok choy and bean sprouts for lunch tomorrow, but when I type in "bok choy" on fitday, nothing turns up. The closest I found to it is Chinese cabbage.

Should I just go with that?

Its on there under "pak choi", which is another name for bok choi.

I'd say yes. This is from wikipedia:

(Cantonese) (also: bok choi, bai cai (Mandarin, 白菜, white vegetable), pak choi and pak choy and sometimes ambiguously known as Chinese leaves) is a green leafy vegetable used in Chinese and South-east Asian cooking. It has a firm white stem, dark green leaves, and a faintly bitter taste. There are a number of different related varieties, some of which have green stems and lighter-green leaves. It is actually a member of the cabbage family (brassica chinensis, or brassica campestris, Chinensis group). Unlike a conventional western cabbage, the heads are very loose and fan outward instead of close in on themselves.

Both the stems and leaves can be used, but the stems take a little longer to cook (though still very little time). It can be steamed or stir-fried. Baby bok choy can even be used raw in a salad if the leaves are very small.

When substitution is required, a mixture of celery and spinach will often work well.

Bok choy is related to:

* choy sum - 1"-wide stalks with some vertical spacing, less bitter, less likely to be damaged due to smaller size
* yu choy - 0.4"-diameter branching stems, rarely sold, may include flowers
* Chinese cabbage - tight head (Pekinensis group), very common

And, according to calorie count.com, bok choy is 9 calories per cup

Nutrition Facts
Serving Size 1 c
Amount Per Serving
Calories
9
Calories from Fat
1
% Daily Value*
Total Fat
0.1g
0%
Saturated Fat
0.0g
0%
Polyunsaturated Fat
0.1g
Monounsaturated Fat
0.0g
Cholesterol
0mg
0%
Sodium
46mg
2%
Total Carbohydrates
1.5g
1%
Dietary Fiber
0.7g
3%
Sugars
0.8g
Protein
1.1g
Vitamin A 63% • Vitamin C 53%
Calcium 7% • Iron 3%
* Based on a 2000 calorie diet

Thank you all!