Other than Michael Bloomberg, the multi-billionaire mayor of New York City, and possibly Rahm Emanuel, the former congressman and Obama chief of staff now mayor of Chicago, the nation’s mayors have a near-invisible national profile.

Not so for Cory Booker, the high-profile, outspoken mayor of Newark. N.J., whose controversial comments early in the presidential campaign rankled Democratic operatives, even as it shined an even brighter light on his political prominence.

Last week, in what some commentators characterized as a stunt, the Newark mayor announced that he planned to live for one week on the equivalent of what program recipients receive in food stamps for a week: About $30.

Allegedly, Booker agreed to live off of food stamps to pay for a week’s worth of groceries, after a twitter follower challenged him to do so last month. He promised to limit himself to about $4 a day for the week, about what USDA guidelines determine is suitable for a one-person household. That’s about $1.40 per meal, assuming three meals a day.

According to a story in the Newark Star-Ledger, by the end of the week, “Booker admitted the challenge was getting tougher, and as media attention for the week-long stint begins to dwindle, so does [his] already meager pile of groceries.”

“I realized early this morning that I am eating too much food per meal,” the newspaper reported on its NJ.com website. “If I do not cut back the amount I am eating at each meal, I will run out of food before the end of the week.”

Thursday his menu included a casserole of peas, beans, cauliflower and broccoli for dinner and a sweet potato for lunch. “I’m worried about my food supplies, which are actually dwindling down and I’m going to have to figure out a way to ration a little bit,” Booker noted in an online post.

According to POLITICO.com, here is a sampling of the type of meals Booker could enjoy on his food stamp diet:

  • Breakfast: One six-ounce strawberry and banana Yoplait yogurt (99 cents) and an eight-ounce carton of Tropicana orange juice (39 cents) = $1.38. Total nutritional value: 290 calories, 57 grams carbs, 9 grams protein, 1.5 grams fat. Plausible, except where can you find 8 oz. of orange juice for 39 cents? Certainly not in Newark in the middle of December.
    • OR Two Safeway eggs (53 cents) and one Oscar Mayer bacon slice (45 cents) = 98 cents. Total nutritional value: 170 calories, 7 grams carbs, 12.8 grams protein and 14 grams fat. A good value but a one that contributes 74% of calories from fat.
  • Lunch: One eight-ounce Eating Right frozen meatball sandwich ($1) and one two-ounce package of Safeway carrots (57 cents) = $1.57. Total nutritional value: 295 calories, 44 grams carbs, 14 grams protein, 7 grams fat. Not bad; but not exactly gourmet fare.
    • OR Two Pantry Essential hot dog wieners (44 cents) with Safeway hot dog buns (37 cents) = 81 cents. Total nutritional value: 294 calories, 50 grams carbs, 20 grams protein and 26 grams fat. Once again, a meal with nearly 80% of calories from fat.
  • Dinner: One sandwich with two Safeway bread slices (28 cents), two Kraft cheese slices (50 cents) and two Oscar Mayer turkey slices (46 cents), $1.24. Total nutritional value: 620 calories, 44 grams carbs, 42 grams protein, 9 grams fat. Ouch. A real jailhouse special.
    • OR One seven-ounce Gorton’s frozen fried fish plank = $1.09. Total nutritional value: 120 calories, 11.5 grams carbs, 4.5 grams protein, 12 grams fat. Not bad nutritionally, but only one fried fish “plank” for dinner? Bon appetit, Mr. Mayor.

Two issues have arisen as a result of Booker’s food stamp diet. One is the amount of assistance people actually receive. Nourishing oneself on $4 a day isn’t exactly Easy Street, although critics point out that food stamps—actually now titled SNAP (Supplemental Nutrition Assistance Program)—are supposed to provide supplemental help, not serve as someone’s sole source of sustenance.

Yet as Booker and his supporters point out, many recipients depend on other programs to pay rent and bills, and SNAP assistance is, in fact, their sole source of grocery money.

Should USDA increase its limits, which would need to be done with legislation? Many consumer advocates strongly agree. Others, however, point to statistics that indicate the lower one’s income, the larger their waistline. Poverty, it seems, despite limiting someone’s food budget, doesn’t seem to control caloric intake.

The answer is obvious by examining the “suggested menus” above: When food dollars are scarce, people naturally gravitate to high-fat, high calorie choices. As even a brief shopping excursion to Whole Foods would confirm, a “healthy” diet—even one consisting of ordinary fruits and vegetables from a conventional supermarket—ain’t cheap.

While there is indeed a minority of people receiving assistance who abuse the system—credible research suggests it’s a very small percentage—most people pulling out their SNAP cards at the store are barely getting by.

Despite his upscale wardrobe and penchant for fine dining, Cory Booker understands that reality better than most mayors. You can’t preside over a stricken city like Newark and remain oblivious to the plight of so many people in poverty.

But there’s another reality connected with this story that is also inescapable: Nobody on food stamps is contemplating the benefits of a vegetarian diet.

Turns out the vegan lifestyle really is a luxury dependent on one’s economic, rather than philosophical, status.

The opinions expressed in this commentary are solely those of Dan Murphy, a veteran food-industry journalist and commentator.