Is Diet Soda Bad For You?

Short answer: No, in moderation.

Long answer: Still no—and here’s why.

Despite all the fear-mongering online, there’s no evidence that moderate diet soda consumption leads to weight gain or negative health outcomes.

It doesn’t spike insulin.

It doesn’t mess with your metabolism.

It doesn’t automatically make you crave sugar or overeat.

In fact, if you swap two full-sugar sodas per day for diet, you’d be saving enough calories to start losing weight—without changing anything else.

So what about aspartame?

Let’s break that down:

• Aspartame is the most heavily studied artificial sweetener in the world.

• The FDA’s acceptable daily intake (ADI) is 50 mg/kg of bodyweight.

• The EFSA (Europe’s version of the FDA) says 40 mg/kg.

For a 150-lb (68 kg) adult, that’s 3,000–3,400 mg per day.

A 12 oz Diet Coke contains about 180 mg of aspartame.

You’d need to drink 18–19 cans per day to hit the upper limit.

That’s over two gallons. Per day.

And even then, the ADI includes a 100x safety margin.

So yes—drink the diet soda if you enjoy it. Just don’t make it your only beverage.

Yesterday we dropped a fresh podcast, waxing on this, and the following topics:

🏃 How much cardio do I need to do without hating my life?

💪 Do bodyweight workouts actually work, and are they worth it?

🔄 When should I switch up my workouts?

Huge shoutout to email subscriber Cami for sending us these topic ideas.

Watch the podcast episode on: YouTube, or listen on Apple or Spotify.

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