Consistency over time, not perfection at every meal
At the start of a new year, many people like to make New Year’s resolutions and set goals to improve their health in the coming year. If this sounds like you, there’s a good chance you’re also considering trying a new diet to help you achieve those goals.

Personalized nutrition is a hype — the idea of doing a DNA or stool test to determine the best diet based on your genetics or digestive system sounds impressive. But beware, many experts say. "There's not enough information out there or studies yet to confirm their effectiveness," says Keri Gans, RDN, author of "The Small Change Diet." The research is still in its infancy, so it's smarter to wait until we have more evidence before handing over your credit card number.
In the meantime, you can do a simple test that works just as well. Here's how:
What are your intentions?
"Look at your reasons for changing your diet," Do you believe in the ethical reasons for going vegan or are you just avoiding animal products because you think it will make you healthier? Did you give up gluten because a celebrity said it helped you lose weight or do you honestly believe you have an intolerance? "Focus on what matters most to you" not what others think is right
Choose a diet or just a change in your diet.
If you're curious about a Paleo, low-carb, vegetarian or... diet, you can try them for a short period of time. Or if you're the type who's considering cutting carbs or cutting out certain foods completely, give it a try. But if you're planning to go that route, only do one thing at a time. Eliminate just gluten or just dairy or just soy. Don't do them all at once, or you won't know which ingredient is causing the changes you're feeling.
Follow whatever you choose for at least a month.
Give it about a month for your body to adjust and start to feel the effects. That said, if you get halfway through and feel like this is completely wrong, don't force yourself - clearly this isn't the right thing for you.
Track what you're doing.
The only way to know if the diet is making a difference is to follow it. You can do this by recording what you eat and how you feel, many people like to use an app. "A food tracker like MyFitnessPal (I actively use it) is a great way to document the foods you've eaten and how you feel after a meal" but choose whatever is easiest for you. However, if you track and record, this can be helpful when trying to identify trigger foods for certain medical conditions, or other conditions that are behind your desire for a dietary change, fatigue, headaches, stomach aches or a desire to lose weight.
Compare and evaluate.
At the end of the test, take an honest look at your logs. If you feel better than you did on your previous diet plan, and you know you can continue this, this is probably your personal best diet. But keep in mind, "You don't have to put an end date on this." Try these changes, see how you feel, give yourself time to adjust, and decide if you want to try something else.
Then your diet can evolve over time to adapt to your lifestyle. Your plan is your plan, so do it without having to put a label on it.
The most important thing in a diet change is that it should feel right for you, only then will you succeed.
I use the word diet, but I could just as easily say lifestyle change, because remember, if you want to succeed, don't set an end date. People often associate a diet with a project that has a start date and an end date, a lifestyle change that you adapt along the way helps you for the rest of your life.