Surprising cause of obesity: Why first-borns and only children are particularly overweight

The link between birth order and obesity

Obesity has become a global epidemic, affecting millions of people worldwide. While there are several factors that contribute to obesity, a recent study has found a surprising link between birth order and weight gain. According to the study, first-borns and only children are more likely to be overweight or obese compared to their younger siblings.

The role of parental attention

One possible explanation for this phenomenon is the role of parental attention. First-borns and only children often receive more attention from their parents compared to their younger siblings. This increased attention can lead to overfeeding and indulgence, as parents may use food as a way to show love and affection.

Furthermore, first-borns and only children may also have more sedentary lifestyles compared to their siblings. With no one to play with at home, they may spend more time indoors watching television or playing video games, leading to a lack of physical activity.

The impact of parental expectations

Another factor that may contribute to the higher rates of obesity in first-borns and only children is parental expectations. Parents often have higher expectations for their first-borns, placing more pressure on them to succeed academically and socially. This pressure can lead to stress and emotional eating, resulting in weight gain.

Additionally, parents may be more lenient with their first-borns and only children when it comes to food choices. They may allow them to indulge in unhealthy snacks or fast food more frequently, as they may perceive them as being more responsible and mature compared to their younger siblings.

The influence of sibling dynamics

Sibling dynamics can also play a role in the weight gain of first-borns and only children. Younger siblings often look up to their older siblings and may imitate their eating habits and lifestyle choices. If the older sibling is overweight or has poor eating habits, the younger sibling may adopt the same behaviors, leading to weight gain.

On the other hand, younger siblings may have more opportunities for physical activity and healthier eating habits due to the influence of their older siblings. They may be more likely to engage in active play or participate in sports, which can help prevent weight gain.

Breaking the cycle

While the link between birth order and obesity may seem concerning, it is important to remember that it is not a definitive predictor of weight gain. There are several steps that parents can take to help prevent obesity in their first-borns and only children.

Firstly, parents should be mindful of their feeding practices and avoid using food as a reward or a way to show affection. Instead, they can find alternative ways to bond with their children, such as engaging in physical activities together or spending quality time outdoors.

Secondly, parents should encourage a healthy and active lifestyle for their first-borns and only children. This can include limiting screen time, promoting regular physical activity, and providing nutritious meals and snacks. By setting a good example and involving the whole family in healthy habits, parents can help prevent weight gain in their children.

Lastly, it is important for parents to be aware of the potential impact of sibling dynamics on their children’s weight. By promoting positive sibling relationships and encouraging healthy behaviors among all their children, parents can create an environment that supports healthy choices and prevents weight gain.


The link between birth order and obesity is a surprising finding that highlights the importance of parental attention, expectations, and sibling dynamics in shaping children’s weight. While first-borns and only children may be more prone to weight gain, it is crucial for parents to take proactive steps to prevent obesity and promote a healthy lifestyle for all their children.

By being mindful of their feeding practices, encouraging physical activity, and fostering positive sibling relationships, parents can help break the cycle of obesity and ensure the long-term health and well-being of their children.