Welcome to the Sweet Side of Science

It's Halloween, which means devil's food is basically required. But this week on PHAT Diaries we're talking blood sugar, so I put a famous Weight Watchers trick to the test: cake mix plus diet soda. That's it. No eggs, no oil, no drama.

I went full chocolate with a zero-sugar devil's food mix and a can of cherry cola, and baked a batch of cupcakes. Then I did the math, because "zero sugar" on a box and "zero blood sugar impact" are not the same thing. Here's what I found, the good and the not-so-sweet.

Ingredients

One box makes about 24 standard cupcakes, or about 18 if you fill the liners fuller.

• 1 box Pillsbury Zero Sugar Moist Supreme Devil's Food Cake Mix

• 1 can (12 oz) Poppi Cherry Cola prebiotic soda, or your favorite diet soda

• Optional: Pillsbury Zero Sugar Chocolate Fudge Frosting

How to make them

1. Preheat the oven to 350°F and line a muffin tin with cupcake liners.

2. Pour the dry cake mix into a bowl, add the soda, and stir until just combined. The batter will fizz a little. That's the fun part.

3. Fill each liner about two-thirds full.

4. Bake 18 to 22 minutes, until a toothpick in the center comes out clean.

5. Cool completely. Frost lightly, or leave them naked.

Tip: Don't overmix. The bubbles help the cupcakes rise, since there are no eggs.

Weight Watchers Points

One unfrosted cupcake is about 2 Points, and about 4 with frosting. The box (12 servings at 4 Points each) plus the can of Poppi (1 Point) adds up to 49 Points for the batch. Split 24 ways, that's about 2 Points per cupcake. The frosting adds about 2 more, based on 3 Points per 2 Tbsp and about 1.2 Tbsp per cupcake.

Numbers assume 24 cupcakes per box and one tub of frosting for the whole batch. Make 18 bigger cupcakes and each is about 3 Points unfrosted. Pile on a full 2 Tbsp of frosting and you're closer to 5 Points, 160 calories and 31 g of carbs.

The Good, the Bad, and the Blood Sugar

Three pros

1. Way fewer calories. About 50 unfrosted or 110 frosted, versus 200 to 300 or more for a typical bakery cupcake. Swapping eggs and oil for soda cuts most of the fat.

2. Almost no added sugar. Even the cane sugar in the soda works out to under half a gram per cupcake.

3. Built-in portion control. One cupcake is one clear serving, so it's easy to track.

Three cons

1. Zero sugar isn't zero carbs. The mix is mostly refined white flour, which can raise blood sugar much like sugar does. That's still about 13 g of carbs per cupcake before frosting.

2. Sugar alcohols still count. The frosting's maltitol raises blood sugar about half as much as sugar, and too much can upset your stomach.

3. Little protein or fiber. There's not much to slow digestion, so the carbs hit fast. Eat yours after a meal or with some protein, like Greek yogurt or a glass of milk.

If you manage diabetes, check your glucose 1 to 2 hours after eating to see how your body handles it, and talk to your care team about fitting treats into your plan.

Shaken, Not Frosted

So is soda cake magic? Not quite. It's math, and pretty good math at that. You get a real chocolate cupcake for a fraction of the usual calories, as long as you remember flour is still a carb and frosting is still frosting.

My verdict: one cupcake, light on the frosting, after dinner. Devil's food, angel's math.

Now I want to hear from you. What's your favorite cake mix and soda combo? Orange soda with yellow cake? Root beer with spice cake? Drop it in the comments, and Happy Halloween from PHAT Diaries!