It’s easy to justify overspending on food. You have to eat.

But I find a lot of families are spending too much at the grocery store and on eating out.

“Is there a percentage considered normal for spending on food and beverage?” a reader asked during a recent online discussion. “To me it is a big budget buster. We spend about 30% of our take-home pay (after tax and savings) on food, which I think is way too much, but my husband thinks is okay.”

In 2018, Americans spent an average of 9.7 percent of their disposable personal incomes on food — divided between food at home (5 percent) and away from home (4.7 percent), according to the Agriculture Department.

Disposable personal income refers to how much money consumers have left after taxes and any other mandatory withholdings are deducted from their paychecks.

Without knowing the size of the reader’s family and their income, I can’t say with certainty that their 30 percent spending for food and beverages is too high. Although, I suspect that it might be.

Last year, households in the lowest income quintile spent an average of $4,109 on food, representing 35.1 percent of income, according to the USDA. Households in the highest income quintile spent an average of $13,348 on food, representing 8.2 percent of income.

“As their incomes rise, households spend more money on food but it represents a smaller overall budget share,” the USDA says.

Families with higher household incomes — more than enough for their needs — should be examining whether they are spending too much on food, including at the grocery store.

This is where I often butt heads with people and their budgets. Eating out they get. It’s a luxury. Yet, they can’t see that they are also wasting money at the supermarket because it’s not seen as an overindulgence. They dismiss the fact that their shopping list had only staples such as milk, eggs and bread — even though they came out with bags of other items they didn’t need. (One easy way to trim your grocery costs: Don’t shop when you’re hungry.)

If you want to determine whether you’re overspending at the supermarket, the USDA provides a useful weekly and monthly guideline. Go to USDA.gov and search for “Cost of Food Reports.”

The food plans, which are put out every month, are broken down into four categories of spending: thrifty, low-cost, moderate-cost and liberal. The USDA lists average food costs for a nutritious diet of meals and snacks prepared at home and bases them on gender and age.

Let’s say you’re a family of five. This includes two adults (the husband and wife are in their 40s) and three children, ages 2, 10 and 12. On a low-cost plan, the average monthly food expenditure for this family would be $1,037.20. Here’s how the costs are broken down on an individual basis in the latest USDA food report:

— Male adult: $242.60

— Female adult: $210.50

— 12-year-old boy: $240.70

— 10-year-old girl: $208.90

— 2-year-old boy: $134.50

But let’s say you’re on a liberal plan. The monthly cost would jump to $1,570 for the family.

Of course this is average spending, so you would adjust your spending according to the needs of your family and any dietary restrictions. Still, assess whether your spending is way out of line.

Food is always one of the hardest areas to trim in a household budget. In my experience, people make a lot of excuses for excess spending in this area. And eating out is the biggest culprit of budget busting.

In 2018, food away from home accounted for 54.4 percent of total food expenditures, according to the USDA.

Think of budget percentage guidelines as you might the recommendations for how many calories you should consume per day. The total number of calories a person needs depends on a number of factors, such as age, weight and level of physical activity.

If you want to lose or gain weight, you adjust the calories consumed.

The same goes with your budget. Set percentage goals for various expense categories to either save more or lose the debt that is consuming so much of your income. You may even need to do both — save and reduce debt.

Yes, you have to eat. But don’t let this basic need bust your budget. If you’re not watching your spending in this area, you could be eating your wealth away.

Readers may write to Michelle Singletary at The Washington Post, 1301 K St. NW, Washington, D.C. 20071 or michelle.singletary@washpost.com. To read previous Color of Money columns, go to http://wapo.st/michelle-singletary.