Motherhood brings about a lot of changes in women – both physically and mentally. Interestingly enough, the same happens to men and they tend to develop what is known as a dad bod, which refers to a soft and round male body type. It is believed that once a man has found a mate and become a father, he doesn’t care much about maintaining his physique. However, there are several other reasons that cause a man’s body to change once he becomes a father. Let’s take a look at these reasons.
1. Hormonal Changes
The fact that women experience hormonal changes during and post pregnancy is well known. However, living with a pregnant partner has been found to affect the hormone levels of men too. Here are the hormonal changes a new father tends to experience.
- Drop in testosterone levels: As men transition into fatherhood, they are said to experience a drop in testosterone levels.1 Though the reasons behind this drop are unclear, it is believed to be nature’s way of keeping the man faithful to his partner. So, he stays close to her and the expected baby. This drop in testosterone levels may continue up to six months after the baby is born.
- Rise in oxytocin levels: Oxytocin, a hormone that plays a crucial role in reproduction and social interaction, is often known as the love hormone as it is also released during rewarding and affectionate physical contact like hugging and kissing. Research has revealed that new fathers experience a remarkable increase in oxytocin levels after interacting with their newborns.2 Just like in mothers, the increased oxytocin levels help fathers bond with their babies as well as be protective of them and eager to provide for them.
id="2-neurological-changes">2. Neurological Changes
Fathers who spend a lot of time with their partner and newborn child experience changes in the brain too. There is increased brain activity after the arrival of the infant, which is said to continue for at least six months. The following reasons contribute to such increased brain activity.
- Increased gray matter in the hypothalamus: The hypothalamus is the part of the brain that is responsible for sensitivity among other functions. New fathers are said to experience an increase in gray matter, a major component of the central nervous system. As gray matter increases in the hypothalamus, it tends to make the person more affectionate, responsible, and adept at multitasking. This is one of the main reasons why men become more emotionally responsive once they start taking care of a baby.3
- Growth of the prefrontal cortex: The prefrontal cortex is the part of the brain that is responsible for functions like planning and memory. When men attain fatherhood, this part of the brain is said to grow and enable new fathers to plan and naturally develop the skills needed for good parenting. Also, the neurons in this region have more receptors for the hormone vasopressin, which is essential for strengthening the bond between father and offspring.4
3. Behavioral Changes
Hormonal and neurological changes in new fathers trigger the following behavioral changes too. These behavioral changes further lead to physical changes.
- Unintentional overeating: Men living with their pregnant partners tend to pick up their eating habits and often end up unintentionally overeating. Also, once the baby is born, the many lifestyle changes and abundant food tend to trigger frequent binging and snacking. This leads to weight gain and the development of the dad bod – the kind of physique with less muscle and more fat.5
- Higher patience levels: Testosterone is usually associated with non-nurturing behaviors. However, when a man attains fatherhood, his testosterone levels drop, making him more inclined toward the needs of his baby. He also becomes less aggressive and more patient.6
|↑1||Gettler, Lee T., Thomas W. McDade, Alan B. Feranil, and Christopher W. Kuzawa. “Longitudinal evidence that fatherhood decreases testosterone in human males.” Proceedings of the National Academy of Sciences 108, no. 39 (2011): 16194-16199.|
|↑2||Feldman, Ruth, Ilanit Gordon, Inna Schneiderman, Omri Weisman, and Orna Zagoory-Sharon. “Natural variations in maternal and paternal care are associated with systematic changes in oxytocin following parent–infant contact.” Psychoneuroendocrinology 35, no. 8 (2010): 1133-1141.|
|↑3||Abraham, Eyal, Talma Hendler, Irit Shapira-Lichter, Yaniv Kanat-Maymon, Orna Zagoory-Sharon, and Ruth Feldman. “Father’s brain is sensitive to child-care experiences.” Proceedings of the National Academy of Sciences 111, no. 27 (2014): 9792-9797.|
|↑4||Kozorovitskiy, Yevgenia, Maria Hughes, Kim Lee, and Elizabeth Gould. “Fatherhood affects dendritic spines and vasopressin V1a receptors in the primate prefrontal cortex.” Nature neuroscience 9, no. 9 (2006): 1094-1096.|
|↑5||Garfield, Craig F., Greg Duncan, Anna Gutina, Joshua Rutsohn, Thomas W. McDade, Emma K. Adam, Rebekah Levine Coley, and P. Lindsay Chase-Lansdale. “Longitudinal study of body mass index in young males and the transition to fatherhood.” American journal of men’s health 10, no. 6 (2016): NP158-NP167.|
|↑6||Swain, James E. “Baby stimuli and the parent brain: functional neuroimaging of the neural substrates of parent-infant attachment.” Psychiatry (Edgmont) 5, no. 8 (2008): 28.|