Why We Gain ‘Happy’ Weight When We’re in Love

Gazing into each other’s eyes over a dripping plate of nachos at your favorite cozy Mexican joint. Cuddling up for a snack-fueled Netflix marathon. Toasting your special connection with the clink of wine glasses.

Falling in love can be downright delicious.

That may be why we tend to gain weight in relationships. While research shows being in a contented long-term relationship has many impressive health benefits, it can also add pounds of “happy weight.” Indeed, one study found both men and women had an increased chance of obesity when they were living with a romantic partner compared to those who were not.

“Couples often experience weight gain due to a phenomenon called behavioral convergence, where individual habits and lifestyles, such as eating patterns and activity levels, begin to mirror each other,” says Ryan Sultan, MD, a teaching psychiatrist and researcher at Columbia University in New York City.

“We may spend more years of our lives with our romantic partners than with anyone else, including our parents,” notes Charlotte Markey, PhD, a professor of psychology at Rutgers University in New Jersey who has studied weight gain in relationships. “Understanding how your partnership impacts your health behaviors and outcomes is a growing area of research.”

Why Do We Gain Weight in Relationships? 

Your weight can creep up for several reasons when you find your special someone, say experts. At the start of a relationship, “going on a date typically involves food,” says Laura Simmons, RDN, CD, of RET Physical Therapy and Healthcare Specialists. “When people eat out, they can view it as an occasion to treat themselves. That means they often consume high-fat or fried foods and get a lot of calories they wouldn’t at home,” she explains.

All the time spent with your new person can mean your former health routine gets crowded out. “Life is busy! Instead of going to the gym or spending time prepping healthy lunches, you may be prioritizing time with your partner,” says Simmons.

As a relationship progresses, you likely settle into shared habits. If your new partner loves a big bowl of ice cream as part of their evening routine, you may find yourself scooping one, too. The fridge might brim with new temptations calling out your name. “When high-calorie foods like chips are readily available in the house, you are cued to crave them. You eat some and get that little dopamine hit — then the craving loop continues,” explains Simmons.

There may be psychological factors at play as well. One theory psychologists offer as to why partnered people gain weight is the “mating market model,” says Markey. Translation: When you are single, you may spend more time and effort dieting and exercising so you can look hot on a dating site and find a match. “In a secure committed relationship, you may feel less inclined to maintain what’s probably an unrealistic body type,” Markey explains. Finally, you get to chill on the sofa after work with your beloved instead of sweating through Pilates! 

It’s important to realize that gaining some weight during such big life transitions is natural, says Markey. Often long-term relationships go hand in hand with body-changing events such as pregnancy and the sleep deprivation of child rearing. “Our bodies change throughout our lives, and that is totally natural. But it’s hard to roll with it in a culture that is obsessed about controlling these changes,” Markey says.

So start with some self-compassion. But if you start feeling sluggish and your non-sweatpants clothing is no longer comfortable, here are some healthy strategies to address this relationship weight phenom.

6 Strategies to Combat ‘Happy’ Weight

1. Take Stock

New relationships often come with lots of life changes — moving in together, an upended schedule, new priorities. The result is you may be neglecting your self-care habits without realizing it. “It is really important to check in with yourself about self-care when you fall into a relationship,” advises Alex D’Elia, RDN, founder of Olox Nutrition. “It can be very easy to put your individual needs to the side while you get caught up in all the togetherness.” 

So pause and take stock, D’Elia suggests. “Ask yourself, are you getting enough sleep, are you feeling more run-down and tired, are you staying up later than usual so you feel more hungry the following day? Are you reducing activity in a way that impacts your mood and energy?” Being aware of your new habits can be a first step toward addressing them.

2. Be More Active Together

Instead of lounging around all weekend, find active ways to have fun together. “Focus on active dates that emphasize movement like pickleball, hiking, or taking a walk,” D’Elia suggests. Try something new: You can check out a climbing gym together or sign up for hot yoga classes. All these fun activities can bring you closer together while giving your health a boost. Research suggests trying novel activities together can increase your sense of relationship security and satisfaction.

3. Eat Mindfully

Love can be distracting. “In the honeymoon phase especially, you are busy talking and laughing during meals. You may not be paying attention to your normal fullness cues,” says Simmons. “Also, we tend to automatically mimic our partner in the amount and the speed with which they are eating.” You might unintentionally eat faster to keep up with your partner and find yourself eating more before you realize you are full.

To get back in touch with your hunger cues, Simmons suggests you pause and check in with yourself during a meal. “Try dividing your main course in half on your plate. When you finish eating the first half, pause and take a few deep, grounding breaths. Tune into how your belly feels. Do you still feel hungry?” If you feel sated, put down your fork and save the rest as leftovers.

4. Get Cooking Together 

“We eat fewer calories when we cook at home compared to eating out,” Simmons points out. So look for ways to make cooking at home more enjoyable. That might mean perfecting your stir-frying technique together or taking a cooking class. Experiment with making healthier versions of restaurant treat foods at home. “For instance, you can make zucchini chips with olive oil and Parmesan in your air fryer. They are crispy and delicious without being deep fried,” Simmons says.

Another fun date idea? Walk around a farmers market, suggests Simmons. “They are full of fresh seasonal produce. You can pick out an ingredient or two that looks interesting and find a recipe to make together.” (Portobello mushroom “steaks,” anyone?) 

5. Involve Your Partner

Getting your partner involved in adopting healthier habits can make the process more successful and might just give you a mutual project to bond over, says Sultan. But bringing up the topic can be delicate.

“I suggest you use language that emphasizes shared benefits and mutual goals,” Sultan says. “Phrases like ‘It might be fun to try …’ frame the conversation positively,” he says. Avoid language that implies blame or focuses on the other person’s habits, such as “How can I lose weight when you always bring home such junk?!” That approach may lead to your partner feeling attacked or resentful. 

Also helpful in these conversations: using lots of “I” statements. “I encourage individuals to lead with their own thoughts and experiences as this prevents defensiveness,” says Courtney Morgan, a licensed professional clinical counselor and the founder of Counseling Unconditionally. “An example may be: ‘I’ve been feeling really sluggish lately and I am hoping to put in more effort to eat healthier.’” If your partner is game to join you in your efforts, you can boost bonding by celebrating milestones like steps walked together.

6. Focus on Your Own Goals

While such buy-in is ideal, it’s possible your partner is not interested in giving up their current lifestyle and eating habits. “One piece of advice I always give to my clients is you can only control your own actions, not those of your partner,” says Simmons.

It is important to understand that your health journey may need to be separate from your romantic relationship, says Morgan. “You can forgo dessert at dinner or go on morning walks, even if your partner orders dessert and sleeps in.”

As in all happy relationships, respect and understanding are key. Sultan recommends leading by example — sharing your own experiences without pressuring your partner. “It’s about inspiring, not coercing. In some cases, one partner’s positive changes and results can naturally motivate the other to join in.”

 

Editorial Sources and Fact-Checking

• Lawrence EM, Rogers RG, Zajacova A, et al. Marital Happiness, Marital Status, Health, and Longevity. Journal of Happiness Studies. July 20, 2018.
• The NS and Gordon-Larsen P. Entry Into Romantic Partnership Is Associated With Obesity. Obesity. September 6, 2012.
• Markey CH, August KJ, Kelly K, et al. Perceptions of Weight Change Among Romantic Partners: Considering Body Image, Relationship Experiences, Gender, and Sexual Orientation. Frontiers in Global Women’s Health. May 20, 2022.
• Cortes K, Britton E, Holmes JG, et al. Our Adventures Make Me Feel Secure: Novel Activities Boost Relationship Satisfaction Through Felt Security. Journal of Experimental Social Psychology. July 2020.