Dieters have been warned to watch their carbs. Investors have been warned to watch their investments in purveyors of foodstuffs high in carbs. But maybe the best advice is that such warnings should be heeded in moderation.

Last night, California Pizza Kitchen (NASDAQ:CPKI) posted healthy gains at the store level and raised its profit outlook. Wait a minute? I thought folks were swearing off the doughy pies! Let's not be so naïve. After a 6.2% jump in comparable-store sales, the company that had guided Wall Street to expect earnings between $0.17 and $0.19 a share is now comfortable with $0.19 or $0.20 for the March quarter.

Sharp investors who figured they could make some serious dough by avoiding the dough-flipping pizza chain might want to rethink that stance. After all, while California Pizza Kitchen's shares are trading lower than when the company went public four years ago, the stock has inched higher over the last two months despite America's low carb way of life.

Earlier this month, Krispy Kreme (NYSE:KKD) posted another strong quarter on a 9% spike in same-store sales. So, why is this Motley Fool Stock Advisor pick performing so well at a time when dieting appears to be all the rage?

No one is calling the low-carb movement a sham. It has clearly made an impact at the grocer level with companies like General Mills (NYSE:GIS) and Kraft (NYSE:KFT) suffering, while others like Campbell Soup (NYSE:CPB) and Kellogg (NYSE:K) are tweaking their lines to stay relevant.

However, while folks are reading labels carefully, it seems they are less discerning when it comes time to treat themselves beyond the kitchen cupboard. No, not every restaurant chain is shining, but the very best seem to be proving that quality is one factor that transcends trends, fads, and movements.

Will trimming back on your carbs as suggested by the Atkins and South Beach Diets really help you trim down? What is a net carb? What are realistic results once you get started? All this and more -- in the Low Carb Way of Life discussion board. Only on

Longtime Fool contributor Rick Munarriz likes his mornings like he likes his doughnuts -- glazed, hot, and original. He owns shares of Krispy Kreme, but he does not own shares in any other company mentioned in this story.