The easiest thing you can do to lose weight: avoid restaurants at all costs

If you want to lose weight, there's one simple thing you can do that will definitely help — and it doesn't require starving yourself, avoiding gluten, or buying magic weight loss supplements.

Just cook at home.

The most recent scientific evidence for this advice comes in the Journal of the Academy of Nutrition and Dietetics, led by Tufts University researcher Lorien Urban. She and her co-authors examined the nutrition content of more than 360 dinner entrees at 123 non-chain restaurants in San Francisco, Boston, and Little Rock between 2011 and 2014.

The restaurant dishes contained 1,200 calories, on average — about half of the 2,000 or 2,500 calories recommended for moderately active women and men in an entire day. American, Italian, and Chinese restaurants were the worst offenders, with nearly 1,500 calories per meal, on average.

Greek, Japanese, Vietnamese, Mexican, and Thai restaurants generally had fewer calories in their dishes. Still, overall the non-chain meals rivaled the calories found in meals at popular chains, and nearly 92 percent of the dishes examined exceeded the energy requirements for a single sitting.

All this suggests you should view the pasta dish at your local Italian restaurant with the same suspicion you reserve for a Big Mac.

The rise in restaurant eating is a big reason for the rise in calorie consumption

This isn't the first time researchers have come to such startling conclusions. As the authors point out, meals consumed out of the home have been recognized as "an important contributor to the increase in energy intake since 1970."

People typically eat 20 to 40 percent more calories in restaurants compared with what they’d eat at home.

A less scientific analysis of restaurant foods, from the Center for Science in the Public Interest in 2014, highlighted some of the most caloric dishes in America for their Xtreme Eating Awards.

The Cheesecake Factory featured heavily on the list. The chain's "bruléed French toast" with a side of bacon contained 2,780 calories (more than a day's worth), 93 grams of saturated fat (about a week's worth), and 24 teaspoons of sugar (about four times the daily recommended intake of added sugar).

That French toast was only rivaled by the chain's creamy farfalle pasta with chicken and roasted garlic, which contained 2,410 calories and 63 grams of saturated fat.

These may be the outliers, not the averages, but they serve as a warning about the extent to which your favorite restaurant foods can derail your diet.

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