If you’ve banned bonbons and sworn off french fries, I don’t need to tell you that New Year’s diet resolutions are among the most popular self-improvement declarations.

But the trouble with telling yourself to make big changes — whether it’s with food or finances — is that it only takes a few slip-ups and you’re back to your old tricks again. That’s why nutrition experts say don’t be so rough on yourself, because adopting healthier eating behaviors takes some time.

In her new book, “The Food Lover’s Healthy Habits Cookbook,” registered dietitian Janet Helm writes, “One recent study found that it takes an average of 66 days before a new habit becomes automatic.”

She adds that long-term behavior change is the result of small victories and little daily tweaks. For instance, when ordering a veggie omelet, ask the kitchen to double up on the veggies and halve the cheese to shave off significant calories and add fiber and nutrients.

Sometimes a new habit means continuing to enjoy the splurge foods you love, but less often.

“Eat your special foods in reasonable amounts,” registered dietitian Jill Nussinow suggests. “If you love cheesecake and eat it a few times a year, that’s fine. Love great croissants? Eat them occasionally, as in when you go to Paris or the best bakery around.”

Be specific

Diet declarations such as “I’ll never eat out again!” are just way too broad to be believed. Helm advises being as specific as possible so goals are action-oriented. For instance, instead of “I’ll be more active,” she suggests “Get up 30 minutes earlier so I can walk in the morning before work.”

Or, let’s say you love Southern foods. Rather than promising to back away from bacon totally, learn to enjoy Southern flavor favorites in moderation.

At Buttermilk Kitchen in Buckhead, share an order of pimento cheese and house pickles with a few friends. Order the grilled chicken sandwich with avocado, spinach, grilled onion and bacon, but ask to skip the creamy ranch dressing. Servers are happy to customize your iced tea by adding just a splash or two of sweet tea to unsweetened tea. Survey the sides to see that you can order a broiled half grapefruit for a naturally sweet and low-calorie dessert.

Resolve to eat more

While most folks think of nutrition improvements as a list of the things they’re not supposed to eat, registered dietitian David Grotto has come up with the lists of food you should be eating more to be healthier.

In his new book, “The Best Things You Can Eat,” he ranks nutrient-rich foods “For everything from aches to zzzz.” For instance, Grotto’s top foods for lowering cholesterol fall into three categories: whole grains, berries and legumes. Garlic, apples and olive oil make the list, too.

Another happy side effect of eating more healthy foods is that they keep you feeling full while crowding out the junk foods and fast foods you may be trying to consume less of in 2013.