If you have lost or gained weight then it can have an effect on your singing voice, in terms of pitch and timbre. A study on classical singers by Rebekah K Smeltzer of the University of Miami, showed that your weight affects your airflow and control too. Body weight makes a difference to how much physical effort it takes for your body to produce a good sound. It is worth remembering that although there are some incredible singers that are heavy - Pavarotti is a good example, they are not better singers because of their weight.
The pitch of your voice
If you are overweight, this has an effect on your singing voice, due to the production and storage of male and female hormones. For men, if you are overweight, you will produce more female hormones, which makes the singing voice sound lighter. You won’t be as efficient at producing a strong, gutsy sound. For women, you will produce more testosterone, which has an effect on the pitch of your voice - you will be singing slightly lower. If you are underweight, the pitch isn’t affected so much, however you are more susceptible to vocal cord injury.
The heaviness myth
Particularly in the world of opera, it has almost been a stereotype that singers are heavier, however this is changing, especially as singers are required to undertake more physical roles and stage work. The fact is that if you are overweight, there is more stress on the body. Breath control is often affected, because of the restricted expansion of the chest. If you are slim, you can still develop as much underlying voice support as heavier people, and the likelihood is that you will have better endurance. Think of your body being like the body of a ‘cello - the space inside gives the instrument a greater resonance. The same can be said of your lungs if you are a singer - unrestricted by body fat, they will produce a bigger sound.
Genetic traits and your voice
Your physical attributes will have an effect on your singing voice too - not just weight. For instance, taller, bigger people tend to have lower voices, due to the length of their larynx and vocal cords. A thicker neck is often present in good singers - think of Tom Jones, Aretha Franklin or James Brown. Compare this say to Michael Jackson, who although had a distinctive voice, wasn’t technically as good a singer, and struggled with vibrato.
Maintaining a healthy weight is best, no matter what style of music you are singing. You will be able to sustain better breathing and endurance.
