Television news loves a crisis, the bigger the better. In the dozen or so years I’ve been scribbling this column, I’ve highlighted dire reports on swine flu, bird flu, global warming and my favorite, Y2K.

“One Nation, Overweight” (9 p.m., CNBC) offers thoughts on another crisis. And this one is obvious to anyone willing to take a gander at their fellow Americans. Or glance in the mirror.

An alarming number of people are tipping the scales at weights seemingly unheard of in previous generations. Is it diet? Environment? Or genes? Correspondent Scott Wagner tried to interview spokespeople for some of America’s biggest corporations, but no one but a lobbyist would answer his phone calls.

Don’t expect CNBC — or any advertising-driven network — to dig too deeply into economic conditions or trends that may exacerbate the problem. No one mentions the systemic decline in real wages over the past four decades. Who can cook healthy when you have both parents working multiple jobs? And who thought it would be healthy to allow corporate advertisers to directly target children, via television, in school and on their computers?

This being CNBC, a cheerleader for Wall Street, we’re told about a pharmaceutical company in California developing a pill that may help people lose weight. It seems only a matter of time before Jim Cramer starts screaming about it on “Mad Money.”

l A week after learning about the “creation myth” behind Jacob and The Man in Black’s eternal feud, tonight marks the last “Lost” (8 p.m., ABC) before the big finale. Not to give too much away, but tonight’s credits include Ana Lucia Cortez (Michelle Rodriguez) and Danielle Rousseau (Mira Furlan).

Tonight’s season finales

• A fateful boat ride on “90210” (7 p.m., CW).

• Exit Val, pursued by a soldier, on “V” (9 p.m., ABC).

Tonight’s other highlights

• Only three remain on “American Idol” (7 p.m., Fox).

• Callen’s cover is blown on “NCIS: Los Angeles” (8 p.m., CBS).

• Neil Patrick Harris guest stars as Schuster’s old rival on “Glee” (8 p.m., Fox).

• “The Wounded Platoon” on “Frontline” (8 p.m., PBS, check local listings) looks at the effects the Iraq War has had on the soldiers of Third Platoon, Charlie Company, 1st Battalion of the 506th Infantry.

• A client offers a peculiar story of self-defense on “The Good Wife” (9 p.m., CBS).

• Squabbles imperil a charity event on “Parenthood” (9 p.m., NBC).

• Women from opposite sides of a conflict look for solutions on “Project Kashmir” on “Independent Lens” (9 p.m., PBS, check local listings).