(Eleanor Davis for The Washington Post)

Kjerstin Gruys, the author of “Mirror, Mirror Off the Wall: How I Learned to Love My Body by Not Looking at It for a Year,” is a sociology PhD candidate at the University of California at Los Angeles.

After a bride-to-be says yes to the dress, she often starts saying no — to carbs, desserts and other high-calorie foods.

When I was planning my 2011 wedding, I felt the pressure to do all I could to look my most beautiful on my wedding day. In our culture, beautiful usually means thin. Indeed, a glance at the top three national bridal magazines published this month found an abundance of weight-loss advice, including “clever ways to shed those last few pounds,” tips for choosing a low-sugar juice cleanse and lists of “bloating” foods to avoid.

But dieting is exactly what brides shouldn’t do if they want to be happy, healthy, calm and confident on their wedding day. Sure, there are plenty of great reasons to be more mindful about your diet and exercise habits, but looking like a twig for your nuptials isn’t one of them. In addition to not working 95 percent of the time, dieting makes us poor decision-makers, depletes our willpower, darkens our mood and can be toxic for our intimate relationships.

Let’s start with the most obvious issue: Diets don’t work in the long run. Numerous studies show that those who diet are more likely to gain weight in the future than they are to lose weight and keep it off. In terms of weight loss or maintenance, we’re generally better off if we never diet in the first place.

Of course, weight gain or loss isn’t the only thing at stake when dieting. Focusing obsessively on our looks makes us dumber. Psychologists have found that the human brain can do only so much at one time, and thinking self-consciously about our looks steals brainpower from other tasks.

In my favorite study on this topic, 72 men and women were required to try on a bathing suit or a V-neck sweater in a dressing room with a full-length mirror. They were then asked to take a math test. Women wearing the bathing suit had significantly lower math scores than those wearing the sweater, presumably because they were too busy thinking about their thighs to contemplate trigonometry.

Thankfully, obsessing about weight or appearance doesn’t dull our minds permanently, but it does leave us less able to perform at our mental best. Choosing a DJ and caterer who fit your budget and drawing up a seating chart are difficult enough on a full stomach, let alone a deprived one.

In a similar vein, activities that require willpower are further brain-draining. Take, for example, an experiment in which one group of college undergraduates was given a two-digit number to remember, and a second group was given a seven-digit number. The students were told to walk down a hall, where they were presented with two snack options: a slice of chocolate cake or a bowl of fruit salad.

The students with seven digits to remember were nearly twice as likely to choose the cake as those who were given two digits. Willpower is finite; all it takes is a few extra bits of information before the brain starts to give in to temptation.

Now imagine the effects of denying oneself those few bites of dessert every day for months on end. I’m convinced that being “hangry” (hungry + angry) is often the first step to becoming a bridezilla.

And let’s not forget about a bride’s most important relationship — with her spouse-to-be. Dieting and having a poor body image can do serious damage to romantic relationships.

For example, a 2010 study by University of Tennessee psychologists found that a woman’s body image accounts for 19 percent of her marital satisfaction and 6 percent of her husband’s marital satisfaction. This should not be surprising; when we feel bad about ourselves, that negativity spills into our relationships. So it makes sense that women with a healthy body image enjoy more frequent and more satisfying sex than do women who are unhappy with their bodies.

But what’s worse is how we ignore our partners’ pleas to stop dieting before the big day. Having someone love you as you are ought to dissuade you from the self-imposed misery of dieting, but many women dismiss their partners’ feelings. “Your opinion on this doesn’t matter,” we insist, as we forge ahead with our vanity agendas.

Within a month of becoming engaged, I was lured into weight-loss fantasies. Despite being a recovered anorexic, I told myself that being a bride-to-be gave me permission to diet, so I spent a few weeks counting carbs and calories. I even bought a wedding dress that was too small, assuming I’d find a way to fit into it. During these weeks I had a short temper and picked more than a few fights with my fiance. At one point, Michael had had enough, declaring, “This isn’t you, or at least this isn’t the side of you I want to marry!” He was right. I was risking my health — and the health of our relationship — for my vanity.

To keep myself from obsessing about my weight, I ended up avoiding mirrors for a year before my wedding. I put fabric over the mirrors in my apartment, cut back on makeup, and I even resisted the urge to sneak a peek at myself in storefront windows. It was enormously challenging, but it forced me to shift my focus away from my appearance and toward more important things such as my relationships, my research and my writing.

I did weigh myself during the experiment. Stepping on the scale was a way I could remind myself that even if I was feeling “fat,” my body was taking care of itself just fine.

Regardless of whether a bride diets before her big day, she will surely care a lot about how she looks. After all, it’s hard to escape the fact that you’re about to be in the spotlight. For this special occasion, paying extra attention to your appearance is normal and can be fun and indulgent.

But for your sanity and that of your future spouse: Indulge in a little cake here and there. That “I’m-marrying-the-love-of-my-life” glow is the most important part of looking your best — and you won’t get it by counting calories.


Read more from Outlook:

How ‘size profiling’ harms overweight patients

Let’s fall in love like the ancients

Friend us on Facebook and follow us on Twitter.