Generally, just fed juvies will show more of a lump in the belly and not such an overall roundness. With the yellow wrapping around like that, it looks to be a more mature speciman and definitely obese, so obese in fact it looks partially puffed. There should be a delineation between the head and body, not that "face on a football" that that fish is showing. Here's an example of one at almost that size in proper body weight.
It looks much better in that picture, maybe it was just the angle but are you sure about th eage and size? An inch a month is the anticipated growth rate, so a 7 month fahaka should be in the 6-8 in range and the yellow on the stomach seems to be more in line with what I've seen for more mature fish.