I Compared 195 Foods Using USDA Data — The Results Changed How I Think About Nutrition

Metra — Wed, 15 Apr 2026 20:57:38 +0000

I wanted to settle debates like "is chicken actually better than salmon?" with real numbers. So I pulled data from the USDA FoodData Central API and built a side-by-side comparison tool for 195 common foods.

The Setup

Every food is compared on 10 metrics per 100g serving:

Calories, Protein, Fat, Carbs, Fiber, Sugar
Vitamin C, Calcium, Iron, Potassium

The tool shows who "wins" each category and gives an overall winner based on total categories won.

5 Findings That Surprised Me

1. Broccoli Has Respectable Protein

At 2.8g protein per 100g with only 34 calories, broccoli has one of the best protein-to-calorie ratios among vegetables. It won't replace chicken breast (31g protein), but for a vegetable, it's surprisingly competitive.

2. Sweet Potato vs Regular Potato Is Closer Than You Think

Everyone assumes sweet potatoes are the "healthy" option. The data shows it's not that simple:

Metric	Sweet Potato	Regular Potato
Calories	86	77
Protein	1.6g	2.0g
Fiber	3.0g	2.2g
Vitamin C	2.4mg	19.7mg
Potassium	337mg	425mg

Regular potatoes actually win on protein, vitamin C, and potassium. Sweet potatoes win on fiber and vitamin A (not shown). It's a genuine toss-up depending on what you need.

3. Almonds vs Walnuts — Not What I Expected

Both are "healthy nuts" but they're surprisingly different:

Almonds: 579 cal, 21g protein, 12g fiber, 269mg calcium
Walnuts: 654 cal, 15g protein, 7g fiber, 98mg calcium

Almonds dominate on protein, fiber, and calcium. Walnuts win on omega-3s (not in our dataset, but worth noting).

4. Egg vs Tofu — The Complete Protein Debate

Per 100g: eggs have 13g protein at 155 cal, while tofu has 8g protein at 76 cal. But tofu has better protein-per-calorie ratio if you're counting. The "which is better" answer genuinely depends on your goals.

5. The Most Nutrient-Dense Foods Per Calorie

When you sort our 195 foods by nutrients-per-calorie, leafy greens dominate: spinach, kale, and watercress pack the most vitamins and minerals for the fewest calories. Not surprising, but the gap is bigger than I expected.

How I Built It

Data: USDA FoodData Central SR Legacy dataset — 195 foods with complete nutrition profiles
Framework: Astro generating static HTML (zero JavaScript, instant loads)
Hosting: Cloudflare Pages (free)
Pages: 18,900+ comparison pages (every possible pair of 195 foods)

The comparison tool lets you pick any two foods and see them side-by-side with visual bars showing who wins each metric.

Try It

The full tool is free at food-nutrition-3xm.pages.dev — search for any food, pick two, compare. There's also a random comparison button if you want to discover surprising matchups.

This is part of a series where I'm building free tools from government data APIs. The solar ROI calculator (using NREL data) was the first — nutrition was the second.

All nutrition data from USDA FoodData Central. Values per 100g serving.

I Analyzed Solar Panel ROI Across All 50 US States Using Government Data — Here's What Surprised Me

Metra — Wed, 15 Apr 2026 20:56:31 +0000

Solar panel ROI varies wildly across the United States — but not for the reasons most people think. I built a free calculator using data from the NREL PVWatts API and EIA electricity rates to compare every state. Here's what the data shows.

The Surprising Finding: Electricity Rates Matter More Than Sunshine

Most people assume the sunniest states have the best solar ROI. The data tells a different story.

Arizona gets the most sunshine (6.54 kWh/m²/day) but only ranks mid-pack for ROI at 2.5x with about a 10-year payback. Why? Because electricity is cheap there — so each kWh your panels generate saves you less money.

Hawaii has the highest ROI at 5.9x with a 4.2-year payback — not because of more sun (5.82 kWh/m²/day, less than Arizona), but because electricity costs are extremely high. Every kWh produced saves significantly more.

Massachusetts beats Arizona on ROI (3.7x vs 2.5x) despite getting way less sun (4.7 vs 6.54 kWh/m²/day). Again — higher electricity rates drive better financial returns.

The Top 5 States for Solar ROI

State	ROI	Payback	Solar Irradiance	Why
Hawaii	5.9x	4.2 years	5.82 kWh/m²/day	Extremely high electricity costs
California	4.5x	5.6 years	5.87 kWh/m²/day	High rates + strong sun
Massachusetts	3.7x	6.8 years	4.70 kWh/m²/day	High electricity rates
New York	2.5x	10 years	4.48 kWh/m²/day	Above-average rates
Arizona	2.5x	10 years	6.54 kWh/m²/day	Best sun, but cheap power

The Worst State

Alaska comes in last at 1.4x ROI with a 17+ year payback. Only 2.4 kWh/m²/day of solar irradiance makes it almost impossible for panels to generate enough energy to justify the cost.

How I Built This

I pulled data from two free government APIs:

NREL PVWatts API — models solar energy production based on location-specific irradiance, weather, and panel angles. Assumes a standard 6kW residential system.
EIA — provides state-level residential electricity rates.

The ROI formula: (annual production × electricity rate × 25 years) / system cost.

I built the calculator with Astro (zero JavaScript, static HTML) and deployed on Cloudflare Pages for free. Each state page lets you adjust system size, cost, and electricity rate to see personalized estimates.

Try It Yourself

The full calculator is free at solar-roi-13a.pages.dev — no signup, no ads. Pick your state, adjust the inputs, see your ROI.

All the data comes from official government sources. I'd love to hear if the estimates match what you've seen from real-world solar installations.

What I Learned

Location economics > weather for solar ROI
Government APIs are underused — NREL, BLS, USDA, FCC all have free, high-quality data
Static sites are powerful — 500+ pages, zero hosting cost, instant page loads
This is part of a larger project where I'm building free data tools from government APIs covering solar, nutrition, salaries, and more.

Data sourced from NREL PVWatts API and EIA. Estimates don't include the federal 30% ITC tax credit, state incentives, or utility rebates, which would improve ROI further.

DEV Community: Metra