November 1, 2025
ByHeidi Godman,
Managing Director
- Reviewed byAnthony L. Komaroff, MD,
Editor in Chief, Harvard Health Letter;Editorial Advisory Board Member, Harvard Health Publishing
As the holiday feasting season approaches, you may be wondering if you can veer off from a <a Some people are more sensitive than others to salt, saturated fat, or added sugars. Blood pressure or cholesterol can be affected in as little as a few weeks after people splurge," says registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women's <a bad" LDL cholesterol and raise your risk for heart disease. McManus advises limiting saturated fat to 7% of your daily calories. To figure out how many grams of saturated fat that would be, take 7% of your daily calories and divide it by nine (one gram of fat has 9 calories). For example, if you're eating 1,500 calories a day: .07 times 1,500 equals 105; 105 divided by 9 is about 12 grams of saturated fat.
What about calories?
Daily calorie needs depend on many factors, including your age, activity level, body composition, overall health, and weight goals (such as weight loss).
If you’re a healthy person who exercises 30 minutes per day, you can estimate how many daily calories you need to maintain your current weight by multiplying your weight (in pounds) by 15.
For example, if you weigh 130 pounds, multiply 130 by 15. The answer – 1,950 – is the amount of calories you need per day to stay at 130 pounds. Eating more could lead to weight gain; eating less could lead to weight loss.
Bending the rules
While a healthy eating plan is crucial for health, bending the rules on occasion probably won’t hurt. A tip you can try is the 90-10 rule. “Eat healthy 90% of the time and splurge 10% of the time,” McManus says. “Eating three meals a day for a week means 21 total meals: avoid splurging for more than two of those meals.”
What about doing a 90-10 plan every day during the holidays, devoting 10% of your daily calories to unhealthy holiday foods? That’s more likely to lead to bad habits. “If you occasionally go slightly over the daily guidelines for calories, salt, added sugar, and saturated fat intake, it’s probably not going to be a problem,” McManus says. “But making every meal a little unhealthy is likely to cause problems.”
Pitfalls
Knowing that you can cheat a little might tempt you to push the 90-10 rule beyond its limits. For example:
You might overdo a cheat meal. It’s easy to consume an extraordinary amount of fat, sugar, and calories in one sitting. Let’s say, for example, that you have a juicy steak, mashed potatoes, and a hot fudge sundae. That rich meal contains 47 grams of saturated fat, 32 grams of mostly added sugars, 1,330 calories, and 2,555 mg of sodium. That would likely meet or exceed the whole day’s targets.
You gain weight and keep it on. Maybe you’ll exceed the <a ll compensate for it in January and February. Unfortunately, studies of what actually happens in the post-holiday period find that many people weigh more in March than before the holidays: January and February didn't fully correct for the holiday splurging. Perhaps you get used to indulging and then can't break that habit. And once you gain weight, your body might reset your metabolism to a higher weight, so you get hungry more easily. "Biology isn't on our side," McManus says.
In other words, unless you make a concerted effort to get back to your pre-holiday weight, your post-holiday weight gain may stick.
What you can do
Try to follow a healthy meal plan on most days, and allow yourself the pleasure of occasionally indulging. “For the holiday season, you may want to enjoy a few particular dishes, meals, or events,” McManus suggests. “Plan ahead for that. But also plan how you’ll be eating when you’re not overindulging.”
Carry that idea through to January and then each month after that. Don’t bargain with yourself; try to maintain an even style of healthy eating, with occasional indulgences. If you use dietary cheating with caution, not abandon, you’ll wind up feeling satisfied that you get to enjoy the foods you love, and you may have more success maintaining your weight goals.
About the Author
Heidi Godman,
Managing Director
Heidi Godman directs all news gathering for Harvard Health Publishing, and also directs the curation and production of HHP’s four monthly subscription publications (the Harvard Health Letter, Harvard Heart Letter, Harvard Men’s Health Watch, and Harvard Women’s Health …
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About the Reviewer
Anthony L. Komaroff, MD,
Editor in Chief, Harvard Health Letter;Editorial Advisory Board Member, Harvard Health Publishing
Dr. Anthony L. Komaroff is the Steven P. SimcoxPatrick A. Clifford/James H. Higby Distinguished Professor of Medicine at Harvard Medical School, senior physician at Brigham and Women’s Hospital in Boston, and editor in chief of the …
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View all posts by Anthony L. Komaroff, MD
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