How Your Diet Affects Your Mood
I recently had one of those rock-bottom, bummed-with-my-body moments. Oh sure, I'd had a few of them through the years, but this time was different. I was 30 pounds overweight and in the worst shape of my life. So I committed to a complete diet-and-lifestyle overhaul, beginning with a one-week fat-blasting jump start involving calorie-torching cardio, plenty of protein, and a scarcity of starch. It wasn't the worst week of my life, but it sure felt like it — to me and my family. If I saw my husband enjoying a slice of pizza, or my 5-year-old son innocently offered me a gummy bear, I snapped at them. I swore at them (OK, just at my husband). I cried into my crudités.
I'm not the only one who gets "hangry" (so hungry that you're angry). According to a recent study published in the Journal of Consumer Research, people who ate an apple instead of chocolate for dietary reasons were more likely to choose violent movies over milder ones and were more irritated by a marketer's message urging them to exercise. I can relate: I rolled my eyes — and may have uttered an audible "Take this jog and shove it!" — at the trainer on my workout DVD as he encouraged me to run in place.
But wait. Shouldn't eating healthfully and exercising make you happy? "It should," says Elizabeth Somer, RD, author of Eat Your Way to Happiness. "But not when you go to extremes or cut out the wrong foods." Oops. So what's the secret to smiling while you slim down? I dove into the research and grilled experts to find out. Learn from my mistakes and get ready to lose weight without the "hanger."
Mood buster: Running on empty
Eat less, exercise more. That's the secret to shedding pounds, right? I thought so, which is why I ate just 1,300 to 1,500 calories a day and burned about 500 most days. My belly rumbled so loudly, I found myself at the computer googling things like killing for calories. No wonder I was irritable: "Changes in brain chemistry that can affect your mood occur when you restrict calories," says Gary L. Wenk, PhD, professor in the departments of psychology and neuroscience at Ohio State University in Columbus, and author of Your Brain on Food. A recent study in Biological Psychiatry noted that when you're hungry, levels of the brain chemical serotonin — a neurotransmitter that regulates mood as well as appetite and sleep — fluctuate and make it difficult to control your anger.
Turns out, being famished goes hand in hand with being frazzled. When researchers at the University of California, San Francisco, put women on a 1,200-calorie-a-day diet, they found that test subjects produced more of the stress hormone cortisol and reported higher levels of perceived stress.
Luckily, there are ways to curb low-cal crankiness. "Cut back slowly, so the body can adjust," says Wenk, who suggests trimming as little as 50 calories a day to start and then gradually more. "This takes time and patience but will help you avoid irritability and mood shifts." Most women need to consume at least 1,500 calories a day — more when exercising — to keep blood sugar stable and energy and mood elevated. "If you're losing more than one to two pounds a week, you're dropping too low," Somer says. I guess my three-pound loss the first week wasn't cause for celebration.
Mood buster: Fudging the fats
I knew I was supposed to eat fish like salmon, mackerel, and sardines, which contain healthy fats that help spur weight loss. Had I actually eaten them, they would also have boosted my mood. Sadly, I'm not a fan of seafood, especially the recommended types, so I opted for a few handfuls of raw almonds instead. I thought it was a good swap, but not so much.
According to research, a deficiency in omega-3 fatty acids — alpha-linolenic acid (ALA), found in plant sources like flaxseeds, soybeans, and walnuts, but not almonds; docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), both found in fish and algae — is associated with depression, anger, and hostility. Getting adequate amounts of omega-3s can actually improve brainpower and mood. "About 60 percent of the brain is made of fat, and omega-3 fats are particularly important for proper neuron function," says Drew Ramsey, MD, assistant clinical professor of psychiatry at Columbia University and coauthor of The Happiness Diet. "These fats decrease inflammation and increase brain-derived neurotrophic factor, or BDNF, a type of molecule that promotes the birth of new brain cells and better connections between brain cells."
Not only do almonds lack the optimum fats for feeding my head, but even nuts and seeds that are rich in omega-3s are inferior to fish. "Animal sources are better than plant sources," explains Dr. Ramsey, who recommends at least two 6-ounce servings of fatty fish per week. Because I have an aversion to the aforementioned fish options, he suggests rotating in other good sources of omega-3s, like shrimp, cod, and mussels, or, alternatively, grass-fed meats or pasture-raised eggs. Personally, I would rather just pop a supplement, and studies suggest that getting about 1,000 milligrams of combined DHA and EPA daily can help improve mood. Dr. Ramsey notes that it typically takes a few weeks to see any sort of effect; other research indicates it can take up to three months.
Mood buster: Going against the grains
As soon as I cut out most sugars and starches, my body started screaming, "Dude! Where's my carb?" and I was angrier than Demi Moore after an Ashton Kutcher sex scandal. This response is apparently not uncommon. According to a recent study published in the Archives of Internal Medicine, people who followed low-carb diets had higher scores on "anger-hostility, confusion-bewilderment, and depression-dejection" scales than those who followed low-fat diets. One possible reason, the researchers noted, was that limiting carbs impedes the brain's ability to synthesize mood-boosting serotonin.
Sugar also stimulates areas in the brain that are linked with pleasure and addiction, Dr. Ramsey says. "All carbohydrates are made of sugar," he explains, "and preliminary research demonstrates that a withdrawal from sugar has similar symptoms to those of an addict withdrawing from heroin." In my case, carbs accounted for just 30 percent of my daily calories. Considering that the Institute of Medicine recommends 45 to 65 percent, it's no wonder I was jonesing for my fix.
Eat, Exercise, and Lose Weight Without Mood Swings
Mood buster: Nixing treats
It's torture for me to watch others indulge in things that I've deemed off-limits. When my husband uncorked the Cabernet, I felt my blood boiling right along with the water for the herbal tea I would be having instead. According to a study published in the Journal of Personality and Social Psychology, it's not the forgoing of food or drink itself but the act of resisting it that's so upsetting. In fact, the researchers found that exerting even a single act of self-control causes a significant drop in blood glucose levels. When blood sugar sinks, it can result in hypoglycemia, which can lead to symptoms that include feeling cranky and acting aggressive. Other studies found that deprivation ultimately backfires, leading us to binge on the very things we are trying to resist.
A simple way to prevent this, of course, is to steer clear of temptation in the first place. "Arrange your environment so that sticking to your eating plan requires as little willpower as possible," advises Sandra Aamodt, PhD, a neuroscientist and coauthor of Welcome to Your Brain. If ice cream is your weakness, don't keep it in the house. And if the office vending machine calls your name every day at 3 p.m., stock your desk drawer with good-for-you munchies like nuts and whole-grain pretzels.
Somer also suggests finding healthy replacements. Clearly, tea didn't quite cut it for me, but the good news is that in moderation treats like chocolate can qualify. In fact, recent research found that consuming 20 grams of dark chocolate twice a day for two weeks resulted in reductions in metabolic signs of stress, including levels of cortisol. "Dark chocolate is quite good for the brain," Dr. Ramsey says. "It is full of compounds that boost mood and concentration." I've also come up with calorie-free substitutions, like climbing into bed with a good book or a trashy magazine and replacing wine with an impromptu couples massage with my husband.
Mood buster: Overdoing exercise
Working out is key to losing weight and staying upbeat — no surprise there. Exercise prompts a change in brain chemicals that lifts your mood. And the effects are almost immediate, says Michael W. Otto, PhD, professor of psychology at Boston University and coauthor of Exercise for Mood and Anxiety. The pick-me-up can happen within just five minutes of completing a moderate workout.
Why, then, wasn't I euphoric after six consecutive days of tough sweat sessions? Because when it comes to the way exercise affects mood, more isn't necessarily better. "A workout that is too rigorous or lasts longer than 60 minutes can dramatically decrease blood sugar, which can affect mood and the ability to think clearly for days," says Michele S. Olson, PhD, a FITNESS advisory board member and professor of exercise science at Auburn University in Montgomery, Alabama.
To ensure that my activities take me to a happier place, Otto recommends being more mindful — paying attention to how my body is feeling and not pushing too hard. "Ratings of mood during exercise can plummet as people get to the point at which it's hard to breathe comfortably," he explains, suggesting that I use the talk test. "If you can talk but not sing during an activity, you're doing moderate-intensity exercise. If you're not able to say more than a few words without pausing for a breath, you are doing vigorous-intensity exercise and should scale it back to maximize your mood." And Olson gives the A-OK to interval training as a way to boost the calorie-torching benefits of exercise without compromising mood. She suggests alternating 30 seconds of high-intensity cardio with 90 seconds of low-intensity. "In my research, interval training improved mood the most," Olson says.
Happily Ever After
All these new strategies have made a huge difference in my disposition. My husband comments on how cheery and resilient — even freakishly enthusiastic — I've become in the face of things that once stressed me out (like a.m. workouts), and my son is literally embracing the new me (no more mad Mommy equals a lot more hugs!). As if that weren't enough, the little guy supports my efforts by offering me healthy alternatives to gummy bears: "Here, Mommy, have some dark chocolate," he says, holding out a few squares. "It's good for you!" Indeed, as I'm sure he now realizes, sharing a treat like that isn't just good for me, it's good for the whole family.
Originally published in FITNESS magazine, March 2012.