A few select items to illustrate what falls where in the rankings: The highest ratio of protein to calories so far is Ball Park Smoked White Turkey Franks, with 45 kcal and 6g protein per dog, or .1333 grams of protein per kcal.
Food.com/Betty Crocker "simple" chili: .1092
turkey dog on a slice of pubilx blended grain bread: .0857
egg, if you can cook w/o oil and eat plain: .0852
Wendy's chili: .0825
lentils: .0783
Wendy's double stack w/cheese: .0675
smilk: .0636
homemade scramble wrap: .0530
Lean Pockets pretzel-turkey-bacon-cheese: .0500
Pubilx Premium blended grain bread: .0500
Dunkin egg+cheese on multigrain bagel: .0471
plain peanut butter: .0400
peanut butter PowerBar: .0375
Banquet turkey pot pie: .0250
Iberia brown rice: .0200
american cheese: .0125
On a day-to-day basis I know I want to run a calorie deficit of ~1000; and I want at least 55g protein, preferably more like 75g. Why so much protein? Because although the body can break down sugars, starches, proteins and fats to glycogen, protein alone has the unique quality of also being the raw building material of healthy lean body mass. The body can synthesize some types of protein from other materials, but not all - these proteins, which must come from dietary sources, are the "essential" amino acids. A sugar-free, low-starch diet, and/or fat-free diet can be healthy and sustainable; but a protein-free diet is fatally incomplete.
Defining junk food. Given that 2160 kcal is my minimum energy expenditure on an "off" day, and 55g protein is my target minimum on any day, suggests a protein-per-kcal index low of .0255. This represents a hypothetical food which, if I ate enough to supply my minimum protein requirement, I could not lose weight without additional exercise. Foods below that index value can be considered "junk" in that I'd have to offset them with higher-index foods and/or more exercise. By this operational definition, that Banquet turkey pot pie is junk food. Sorry, Banquet. Interestingly, even a chocolate Powerbar exceeds the minimum index by ~30%. Not a great choice, but not necessarily a bad choice either.
And now, health food. Given a target average daily kcal deficit of 1000 under 2160, and 75g is my optimal protein target, suggests a protein-per-kcal target of .0647. This represents a hypothetical food that if I ate only enough to meet the safe kcal deficit of 1000 on an "off" day, would still supply an optimal abundance of protein. Foods at or above that index value can be considered "healthy", in that they fully support the additional protein demands of strenuous exercise, without eclipsing the goal of calorie deficit. By that reckoning, the Wendy's double-stack is a surprisingly healthy choice!
Looking forward, we know that the "baseline" of 2160 kcal/day is dependent on my current weight of 200#. As a body loses weight, it takes less energy to sustain the remaining body mass. Ergo as I trim down, calculations involving that baseline will have to slide as well. For example, let's say I reach the ideal weight for my height according to the Hamwi formula: 163#. According to the HealthStatus.com activity calculator referenced Tuesday, a 163# body burns 78 kcal/hour sitting, vs. 96/hr at 200#. Calculating proportionally by my estimate that I average 90 kcal/hr expense on an "off" day, at 150# the same activity level costs only ~73 kcal/hour or 1752 kcal.
Running a daily 1000 kcal deficit to shave off those last few pounds would mean a dangerously low intake of only 750 kcal on "off" days. Not only that, the energy cost of exercise will also drop off - where 3.3mi at 5.1mph might cost, say, 600 kcal at 200#, it will drop to maybe 500 at my Hamwi ideal weight, and I'll have to increase speed, distance or both to keep up the kcal expense. I'm not terribly concerned about the latter; with steady practice I know I can get back to my Marine-grade sustainable 6.1mph pace. I do worry that decreasing loss-per-week progress will discourage and stall me.