Complaining about school lunch is a time-honored tradition. But teens on Twitter have found someone new to blame, tweeting photos of tiny and/or disgusting-looking school lunches with the hashtag #ThanksMichelleObama:



Because healthy eating, particularly for kids, is one of the First Lady's signature issues, it makes sense that she'd be associated with changes to the federal school lunch program. But those changes actually started with Congress and were put into place by the US Department of Agriculture.

Congress passed the Healthy, Hunger-Free Kids Act in 2010, requiring the federal government to issue school lunch guidelines based on recommendations from the Institute of Medicine.

Based on the photos above, the act might not always be living up to its name.

Why the federal government changed school lunches



The new regulations from the US Department of Agriculture require school lunches to meet higher nutritional standards. Meals are now supposed to have more whole grains, less meat and less sodium than in the past, and they have to include at least one fruit or vegetable.

Schools also have to offer a wide variety of vegetables — in one week, they have to offer starches (such as potatoes), dark green vegetables (spinach, kale, and other greens), red or orange vegetables (such as carrots or beets), and beans or peas.

If students refuse to put a vegetable or fruit on their tray, the school isn't reimbursed for that meal.

Why school lunches look so gross



Anybody who went to school can tell you that gross-looking school lunches aren't new. But the new school lunch guidelines sound like they should lead to healthy, whole-grain rich meals — not the pizza, chicken nuggets, and hamburgers that were mainstays of school lunches in the past.

Why hasn't it worked out that way? Partly because school lunches need to be cheap. When California began a pilot program of serving fresh, local food one day a week, one district learned that two free-range chicken drumsticks for a high school student would cost 80 cents, more than the 60 cents they're supposed to spend on an entree. Healthier meals also require equipment that school kitchens, set up to reheat and serve batches of processed foods, sometimes don't have.

Districts are also allowed to make agreements with food companies to turn the raw ingredients they get from the US Department of Agriculture into processed foods, ensuring they have a constant supply of chicken nuggets. Schools didn't stop offering pizza at lunch, a study in the journal Childhood Obesity found: they just started offering healthier pizza, whatever "healthier pizza" means. (It probably doesn't taste as good.)

Why vending machines are empty



#ThanksMichelleObama is almost accurate here, if you can imagine Michelle Obama standing in for the US Department of Agriculture. (It is part of the executive branch!) For the first time, the USDA now regulates foods that schools sell outside of the school lunch program — the sweet, salty snacks in vending machines and a la carte lines.

Students used to eat a lot of unhealthy food during the school day. In the 2005 school year, the USDA says, students drank 452 million sodas, 26 million diet sodas, and 864 million fruit drinks. They ate 763 million candy bars and 1.4 billion desserts. On average, high school students who ate those foods consumed an extra 277 calories a day, the majority of them empty calories from foods without much nutritional value.

But beginning this school year, everything sold in schools — even outside the national school lunch program — has to meet nutrition guidelines. Snacks must be under 200 calories, and foods must have some nutritional value — rich in whole grains, or have fruit, vegetables, protein, or dairy as a main ingredient, or contain 10 percent of the recommended daily value of important nutrients.

So it's not just Michelle Obama to blame — in fact, technically, she had nothing to do with the regulations. But #thanksCongresstheUSDAandschoolmealbudgets is a bit of a mouthful, as hashtags go.