A Wall Street Journal story about the increasing demand for foods that say “protein” on the packaging, http://on.wsj.com/ZsMZhK, highlights the careful use of words for a persuasive effect.

For nearly a century, marketing people and politicians have carefully chosen words that have positive connotations, because those words influence the way people think about a product, issue, or person. And because of the connotations, a word can mean different things to different people. For some, the WSJ article notes, protein means muscle-building, to others, it means energy, and to others protein makes them feel full.

The truth is, most people don’t know much about protein and exactly what it does for the body, which is why marketing people are smiling. Persuasive tactics work because shoppers are not skeptical enough, they don’t ask enough questions, and they don’t read the small print. Similarly, they grab vegetables, cereals, and countless other products that say organic or all natural, even though they know little about what those terms mean.

Before paying more for products that say “protein,” check to see how much protein it contains, and learn how much protein your body needs in a day. Many people consume more protein than they need, and other sources of protein might yield greater benefit than a product that has a little protein and plenty of sugar and sodium.