Katherine Bauer, an epidemiologist who is an assistant professor in the department of nutritional sciences at the University of Michigan School of Public Health in Ann Arbor, cited what she called “the prevalent belief that people don’t know they’re heavy, and if we just inform them they will magically be motivated for behavior change.” In fact, she said, weight stigma does exactly the opposite; criticizing and inducing shame only make people feel terrible about themselves, not motivated or capable of making changes.

We are all, including our children, living in a culture that is profoundly critical of excess weight and at the same time constantly offering opportunities and advertisements for overindulgence. “It’s important to focus on positive reinforcement and not jump to negative,” Dr. Pont said. What this means, for parents and for health providers, is to make sure we see the child, not just the number on the scale. “Recognize that a child is far more than what their weight is, praise them for all the positives, so when we get to some of the more challenging topics, they can still maintain their self-esteem,” Dr. Pont said.

And that time in the exam room has to include talking about nutrition and exercise, but “the focus should be on health or health behavior rather than looking thin, fitting into certain pants,” Dr. Puhl said. So it’s absolutely reasonable to talk about eating patterns, about family meal times, about what foods kids choose at home and at school, about screen time and exercise. Of course, excess screen time or too much junk food are problems even if you’re thin.

The most effective way for parents to help a child is to make healthy changes for the whole family, regardless of shape or size, Dr. Pont said. Try making small changes slowly, like adding one new green vegetable into the family diet, not keeping sugary drinks in the home or walking to school instead of driving.

And yes, to bring up the big turkey in the room, Thanksgiving is upon us; here come the relatives. If you have a child for whom this is a sensitive subject, try to make sure that no one spoils that child’s day. When it comes to a child’s weight or eating habits, “the Thanksgiving table is not an appropriate place to be commenting,” Dr. Puhl said.

“Public discussions at the table that are teasing or negative are not helpful,” Dr. Messito said, and some people will overeat in response to feeling stressed.

And all the experts recognize that one essential message to children is that however important healthy changes in their diet may be, they can still enjoy special days and special treats and special meals. “Enjoy the holiday; make the changes not on a holiday,” Dr. Pont said.

“Food is our way of connecting with people, especially around Thanksgiving, our way of bringing people together and showing thankfulness,” said Dr. Bauer. “Let’s have a shaming-free Thanksgiving where we just enjoy ourselves.”