Almost half of Brits (48%) gain weight after starting a relationship, with more than one in 10 (11%) seeing that change within the first four to six months.
This data comes from a new survey conducted by the Chemist4U weight loss experts, which examined the impact that relationships have on weight gain.
In general, men were found to feel more confident about their bodies when in a relationship, with almost half (45%) saying they feel more confident, compared to a third (31%) of women.
Interestingly, almost one in three (27%) of women revealed that they actually feel less confident in their body once they start seeing someone. That’s 13 percentage points more than men – just 14% felt less confident about how they looked after starting a new relationship.
64% of those between the ages of 25 and 34 reported feeling more confident when in a relationship, while the age group that feels less confident was discovered to be 45-54 year olds (33%).
Jason Murphy, head of pharmacy and Chemist4U weight loss expert, said: “Both positive and negative emotions in relationships can affect your weight, but the negative ones usually hit harder. Happy times can mean shared meals and cosy nights in, which may lead to slow, routine-based weight gain.
“But when we’re stressed, we crave quick comforts. That means reaching for things like sugary or fatty foods, which we end up overindulging on. This can lead to more rapid weight gain. Instead, plan to have healthy snacks on hand if you’re worried about emotional eating. Fruit, nuts, dark chocolate with high cocoa or yoghurt can give you a boost and keep you full without the guilt afterwards.
“At the end of the day, emotional eating can contribute to weight gain, whether it’s triggered by happiness or sadness. What matters most is recognising it and making healthier choices to manage it.”
Women are more likely to see weight gain
Almost half of both men (47%) and women (50%) said they had gained weight since starting their current relationship. One in five men (21%) and women (20%) reported gaining between 5-10kg since starting a relationship. More than one in ten (11%) also say they have gained 10kg+.
The most significant difference is between men and women who reported their weight hadn’t changed at all since they began a relationship. More than a third of men (35%) saw their weight stay the same, compared to less than a quarter (23%) of women.
Jason Murphy, Chemist4U weight loss expert, said:
“All sorts of things can spark cravings: changes in blood sugar, stress, lack of sleep, even pure habit. That 3pm chocolate fix? Often, it’s just your body reacting to an energy dip after lunch or a routine you’ve developed over time.
“Being in a relationship can influence cravings, and it cuts both ways. Shared food rituals like Friday night takeaways can encourage less healthy habits, but a supportive partner can also make it easier to stick to positive changes.
“But it’s not about monitoring each other; it’s about being a team. That might mean cooking healthier meals together, going for a walk in the evening, or simply respecting each other’s goals.”
Jason’s top tips for maintaining a healthy weight in a relationship:
1. Get ahead of the triggers: eating balanced meals and staying hydrated keeps blood sugar steady and stops you from mistaking thirst for hunger
2. Stock the fridge with foods that support your goals: Treats are fine in moderation, but a high protein and low ultra-processed diet is key
3. Plan activities together: whether that’s a long walk, a new hobby like swimming or tennis, or a couple’s gym session to motivate each other to success
4. Celebrate each other’s progress: teamwork makes the dream work, so take the time to say well done
5. Thrive together: you’re not just helping your partner, you’re building a lifestyle that lets you both thrive
One in 10 gain weight after the honeymoon phase
According to the survey’s results, men are more likely to gain weight faster than women after starting a relationship. Of the men who did gain weight in a new relationship, it was most likely to happen between four – six months into the relationship (14%).
For women ,it takes a bit longer: 11% said they began gaining weight after between one – two years – just as the “honeymoon phase” comes to an end.
