This viral, heartfelt letter to Demi Lovato written in London's tube packs the feels.

Whether you’re stuck in a slump or having trouble finding motivation at work, when melancholy strikes, there’s nothing in the world that more appealing than lying in bed for hours. But what if there were a simple tool, like a checklist, that could help pinpoint the reason you’re feeling so glum?

Meet Michael Plant, a 36-year-old global happiness researcher at the Happier Lives Institute, a unique nonprofit that “connects people and organizations together to fund happiness and improve wellbeing around the world.” He’s also a postdoctoral research fellow at Oxford University’s Wellbeing Research Centre, which is responsible for publishing the world’s foremost annual publication on wellbeing, the World Happiness Report. To put it plainly, the man knows how to feel good.

During an interview with CNBC, Plant shared his wisdom: “I have this mental checklist I run through that I write down. So if I’m in a bad mood, I check it,” he explained.

“Have I eaten something? Have I left the house? Have I spoken to someone? And have I exercised? Once I’ve run through those four, if I’m not feeling better, then it’s quite serious.”

Could finding joy really be that simple? The beauty of his checklist lies in its simplicity: by addressing the basic physical and social needs of our bodies first, we might be able to bypass the rushed, hasty conclusions that almost always lead to nowhere. Let’s breakdown each question and why they’re so essential to overall wellbeing.

Question #1: Have I eaten something?

Eating the right foods is crucial for mental health. media3.giphy.com

Our bodies need fuel. A statement that may feel as obvious as “the sky is blue,” but hunger has an enormous impact on our moods and cognitive function. There’s even an entire discipline dedicated to researching the link between what we eat and mood disorders, like depression and anxiety, called “nutritional psychiatry."

In a study published in the Journal of the Missouri State Medical Association, researchers found that several nutritional deficiencies, such as vitamin B12, B9, and zinc, can cause depression and dementia-like symptoms, including low mood, fatigue, cognitive decline, and irritability.

“Like an expensive car, your brain functions best when it gets only premium fuel. Eating high-quality foods that contain lots of vitamins, minerals, and antioxidants nourishes the brain and protects it from oxidative stress... which can damage cells.”
- Dr. Eva Selhub for Harvard Health.

Luckily, you don’t need to seek out expensive supplements or fancy treatments to get back on track.

Vitamin B9, also known as folate or folic acid, naturally occurs in “super” foods like dark leafy greens (kale, spinach, collard greens), legumes (lentils and beans), and nuts and seeds, Similar to B9, zinc-rich foods include shellfish, eggs, red meat, and dairy products.

For an extra bump in Vitamin B12, look to animal products like red meat, chicken, milk, eggs, dairy, and fish. Vegans, however, must be extra vigilant: Stephen Walsh, a Vegan Society Trustee, warns that to avoid deficiencies, vegans must eat fortified foods found in select plant milks and breakfast cereal or take supplements.

Legumes, like beans and lentils, are super foods and chockful of Vitamin B9. Photo credit: Canva

Question #2: Have I left the house?

Exposure to the outdoors is central to Plant’s daily routine. And for good reason: a groundbreaking study published in Scientific Reports indicated that a growing number of epidemiologists are encouraging people to embrace natural environments (think beaches, parks, and woods) on a more regular basis, due to their massive health benefits.

The same study found that spending at least 120 minutes per week in natural environments–just two hours!–significantly lowered cortisol levels, blood pressure, and mental fatigue, while also improving overall mood and cognitive performance: a true win/win.

Spending time in nature for at least two hours a week is great for overall wellbeing. media4.giphy.com

If you, like many others, struggle with getting outside enough, start small. Try eating lunch outside, or take a phone call while walking around the neighborhood. Every moment counts, and even a short five-minute stroll outside could help elevate your mood and reduce stress.

There's an innate need for human connection.media0.giphy.com

Question #3: Have I spoken with someone?

Plant’s third question on his mental checklist recognizes the innate, human need for social connection. In the longest-running study on happiness to date, over 700 people from across the world allowed scientists to monitor and examine their lives and health records for 85 years. It was the Harvard Study of Adult Development, and researchers found that the key to living a long, happy, and healthy life is lies in nurturing your relationships: spouses, family members, friends, and even your acquaintances.

"The surprising finding is that our relationships and how happy we are in our relationships has a powerful influence on our health. Taking care of your body is important, but tending to your relationships is a form of self-care too. That, I think, is the revelation.” - Dr. Waldinger, the psychiatrist who directed the Harvard study.

Plant echoes this, recommending: “Branch out: Do you have weaker ties with people who you see every now and then, who make you feel like part of a community? You have to actively work to form social bonds.”

Question #4: And have I exercised?

Why is Plant’s final question about exercise? It’s because the link between your physical health and mental health are inextricably tied. If one falters, so does the other.

Research on the relationship between exercise and depression found that regular physical activity “releases endorphins, boosts neurotransmitters (serotonin, dopamine), and can match the efficacy of psychotherapy and pharmacotherapy for mild-to-moderate depression.”

Even a simple hike, no matter what the pace, is effective when combatting feeling bad. Photo credit: Canva

That doesn’t mean you have to be Michael Phelps or do Olympic-level training just to feel good. A slow-paced hike on your favorite trail is just as effective as training for a triathlon when it comes to mental wellbeing.

Even just 11 minutes of moderate exercise per day can change your life: it reduces all-cause mortality (death in general) by 23% and lowers the risk of cancer by 7%.

Feel like an impossible task? Try incorporating a few low-effort strategies into your daily life:

• Taking the stairs when possible
• Intentionally park further away, or get off the train or bus a stop early
• Walk during your lunch break
• Use a step tracker to stay aware, either with an app or a physical pedometer, like this vintage digital one that fits in your pocket.

Tracking your steps can help motivate you and keep you motivated. media0.giphy.com

Dr. Michael Plant’s four-part checklist may be simple, but aren’t many of the best things in life? This useful blueprint maximizes daily happiness—and quells any fears that something might be seriously wrong with us.

"I don’t think that’s reasonable," he says at the end of the interview regarding “good vibes only” culture. “We should try for good vibes, mostly.” Straightforward and practical, the next time you’re feeling out of control, consider Dr. Plant’s sage four-question checklist.