Here's your Forbes Daily Briefing for Friday, December 13th.

Today on Forbes, this Protein Bar co-founder sold his company for $600 million.

Now he wants another bite of the market.

Sitting at a table at Balthazar in downtown Manhattan,

Peter Rayall spears a piece of smoked salmon on his plate

and ignores the nearby toast. The 38-year-old co-founder of Nutrition Bar brand RX Bar

thinks about protein constantly, and not just for his own health. Rayall has been dreaming of creating

a new bar since the day he and his co-founder, Jared Smith,

sold RX Bar to Kellogg's for $600 million in 2017.

Rayall made that dream a reality in September when he launched David,

or so he calls it, quote, the final protein bar.

Having made a pre-tax $300 million from his 50% share of the

RX bar sale, Rayall led David's $10 million seed round this year with an investment of $6 million.

Named after Michelangelo's 16th century masterpiece, David claims to be the most protein-dense bar in existence

and is backed by high-profile physicians and health podcasters Peter Attea, who is also a

minority investor, and Andrew Huberman. With 28 grams of protein and just 150 calories, the compact

snack currently comes in four flavors and sells

exclusively direct-to-consumer for $3.25 per bar. Rayall says, quote, I've been in the nutrition

bar space for 20 years through all the changes, from Atkins to keto to paleo to fasting, to

carnivoreore to whatever.

But there are two consistent things that have driven the category.

The desire for muscle gain and fat loss.

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