You’re at your desk focusing on the computer screen when your eyelids begin to droop. It’s about 3 p.m. and your stomach begins to pang its incessant hunger signal right on cue. Lunch was just hours ago, but it has quickly become a distant memory.

There are a number of physiological reasons why the infamous three o’clock hunger hits. The body is set up with a system that carefully calculates how much energy (calories) it needs to carry out basic functions, like keeping your heart beating, lungs pumping, and brain thinking. Basal metabolic rate (BMR), the key to this whole system, regulates how the body expends energy and at what pace. An individual’s BMR is based on a number of factors, including the body’s fat-to-lean muscle ratio, exercise frequency, number of calories, and genetics.

Why 3PM Hunger Happens

Most of the food and drinks a person consumes is turned into glucose, the sugar that’s circulating in the blood. When a person overeats, the extra glucose is stored in the body’s fat so that it can be used later on, if needed. However, when the body senses it isn’t receiving, or at least maintaining, the calories it needs, BMR slows down by up to 45 percent so that it can conserve energy.

Once blood sugar levels start to drop off, the liver sends a signal to the brain telling it to start eating again. As the body finishes digesting a 200- to 500-calorie lunch and turning it into glucose for immediate energy, the pancreas produces the hormone insulin, which signals hunger and converts stored glucose into fat.

After the lunch is fully digested, it uses up some of that stored fat as energy, but the liver also sends a signal to the brain’s hypothalamus to stop the body from releasing all of its energy stores. In response, the hypothalamus releases hunger-triggering hormone orexin while the stomach produces another hunger hormone ghrelin, which stimulates the hippocampus, a brain region responsible for learning and memory — just in case you forgot where to find food.

Packing A Better Lunch Box

A daily balanced meal of just the right blend of fruits, vegetables, carbohydrates, proteins, fats, vitamins, and minerals are necessary to keep the body running at top efficiency, but there are a few meal choices that can help a person stay feeling satisfied until dinner and skip the slump. Fortunately, there are a few key nutrients that can help you the body maintain a sense of fullness and avoid spiraling into a pit of hunger spurred by the secretion of hormones and signals designed to send you to the vending machine or office fridge.

Here are three nutrients known to help keep the body full between meals, and a few easy-to-follow recipes that can help guide you toward eating a better, healthier lunch.

Fiber

By eating larger portions of low-energy-dense foods, you’ll be able to eat fewer calories in a larger meal, which will help you stay fuller for longer. According to the Mayo Clinic, high-fiber foods also take longer to digest, which keep the stomach from releasing hunger signals to the brain. Air-popped popcorn is full of fiber and whole grains, but low in calories. It could be used as an additional side snack.

1. Grilled Eggplant & Portobello Sandwich

2. Mediterranean Tuna Wrap

3. Turkey and Pepper Tacos

Protein

While fiber makes a person feel full right away, protein maintains the feeling for longer. Animal and plant-based proteins each have their own pros and cons, with animal protein having more naturally occurring saturated fats and plant-based proteins providing fewer protein calories. Protein is a necessary part of a person’s diet because it’s used to build and repair cells for healthy muscles, organs, glands, and skin maintenance. The Institute of Medicine recommends 0.8 grams of protein per kilogram of body weight.

1. Three-Bean Chili

2. Chickpea and Kale Stew

3. Mexican Quinoa Salad

Good Fat

It may surprise you, but fat is the last key to staving off hunger. While fiber and protein work together to keep the body feeling full, fat works with the body’s hormones, signaling it to stop eating. Fat, unlike fiber, is high in energy density. If there happens to be a large gap between lunch and dinner because of date night reservations or plans after a show, a mix of almonds, walnuts, cashews, and sunflower seeds can provide a good blend of fat and protein to keep the body from ruining its appetite.

1. Avocado Chicken Salad

2. Vegetable Egg Frittata

3. Caesar Salmon Pita Pockets

If It’s Not Your Diet, It Could Be…

If bouts of hunger between meals still persist despite making alterations to your diet, then your sleep cycle may be to blame. Sleep is intricately responsible for the proper functioning of so many brain and body processes, including having a strong immune system, respiration, cardiovascular health, blood pressure, appetite, and mental health. According to the National Sleep Foundation’s most recent recommendations, written by a panel of medical experts, adults between the ages of 18 and 64 should get at least seven to nine hours of sleep.

Failing to clock in those hours can lead to an increase in ghrelin, the appetite-stimulating hormone, and a decrease in leptin, the appetite-suppressing hormone. When the body is short on sleep, the prefrontal cortex, a part of the brain that controls impulses and weighs consequences, doesn’t work at full capacity and can lead a person to give in to their cravings.