There was a time when the front door would swing wide open at 2:40 p.m. every day. The volume in the room would explode, and you’d have thought a herd of elephants was charging in. I learned quickly not to obstruct the line from the doorway to the fridge.

As a work-from-home mom living just a few blocks from the high school, my house was the food destination for my two starving daughters and several of their teenage friends clamoring for leftovers.

There was a time when I was making at least two trips to the grocery store every week, and very little food was thrown out. However, today, with both girls gone to college, the house is remarkably quiet. My pantries are overstocked; the freezer is full; and sadly, I have not adjusted well — albeit, I’m getting there. There is some psychological emptiness to this empty nest, but I’ll keep this column focused on food.

There was a time when each trip to the store included, among other things, two gallons of milk, family-sized meat packages, multiple boxes of cereal, a bottle of ranch dressing, and five or six cucumbers at a time — staples for teenage girls.

It’s been almost a year since the house had a teenager living in it, and I’ve got a problem. I don’t know how to shop or cook anymore, at least not for two.

Several cucumbers have mutated into a gelatinous mass, and leftovers have been left in the fridge way too long. Milk has soured, and yes, I’ve even tossed chicken parmesan — something simply unheard of when the house had more life in it.

I was brought up to never be wasteful, but lately I’ve thrown out way too much food, which is bothersome to me. I am not only spending money on unconsumed food, but also squandering the water and energy used in its production.

And then there’s the environment. The decomposition of food and other organic waste in landfills produces methane, a greenhouse gas 21 times more damaging to the environment than carbon dioxide. Landfills are the largest human-related source of methane in the U.S., accounting for 34% of all methane emissions.

Food waste happens at multiple levels, from the field and factory to retail outlets and our homes, schools and restaurants. It’s been identified and even quantified.

31% of food wasted
According to a USDA study, in the U.S., 31%, or 133 billion pounds, of the 430 billion pounds of the available food supply at the retail and consumer levels in 2010 went uneaten. Retail-level losses represented 10% (43 billion pounds) and consumer-level losses 21% (90 billion pounds) of the available food supply.

Losses on the farm and between the farm and retailer were not estimated due to data limitations for some of the food groups.

The estimated total value of food loss at the retail and consumer levels in the United States was $161.6 billion in 2010.

Today, there is a renewed interest in the issues related to food loss, and schools are adopting programs, educating students on correct portion size (multiple benefits to this) and providing options to donate their unwanted, packaged food items.

The U.S. Environmental Protection Agency’s food recovery hierarchy prioritizes actions organizations and businesses can take to prevent and divert wasted food to feed hungry people.

Much of household waste is due to overbuying, food spoilage and plate waste. In my house, most of my food waste is from prepared food not being eaten.

There was a time when leftovers helped feed what seemed like half the neighborhood. Now from time to time, I will package up leftovers and do my own take on Meals on Wheels to my college girls. But times have changed, and I vow to do my part to change, which starts with better planning and purchasing. Learning to cook for two will be an adjustment.

U.S. Secretary of Agriculture Tom Vilsack has set a goal to reduce food waste by 50% by 2030.

Hopefully, by being much more mindful of food loss and implementing new practices, there will be a time when we will look back and be proud of our progress.