“Maria Callas's significant weight loss in the 1950s caused a deterioration in the quality of her singing voice, as debated by musicologists.”

Two phoniatric experts, Franco Fussi and Nico Paolillo, have presented the results of their research at the University of Bologna, which revealed that in her last period Callas had de facto become a mezzo-soprano. They pointed out that, on the basis of recent cases, a weight loss can cause a decreased physical support of the vocal apparatus and a lesser homogeneity between registers.

Critic Conrad Osborne says Callas' voice was already starting to fail her by the time she was in her 40s -- quite young for an opera singer. A number of factors, including a rapid loss of weight, may explain why. But Osborne, who also teaches voice, says Callas lacked the proper technique to sustain her ambitious repertoire.

Maria stopped performing after struggling with her voice, likely due to overuse, her extreme weight loss, dermatomyositis, and addiction. Maria had dermatomyositis, a disease that involves muscle inflammation and a skin rash, which can impact the vocal cords and caused Maria to lose her powerful voice.

Some have argued that a noticeable loss of weight around 1953/54 were the cause of these vocal difficulties, or that her training was inadequate. To be sure, there were problems. But anyone who listens to two of Maria Callas's greatest roles – 'Casta diva' from Bellini's Norma and Tosca from 1965 (the only existing footage of a Callas role) – cannot fail to be moved by the expressive power of her acting and singing in combination.

Experts and fans alike continue to question what exactly happened to a voice that was both exhilarating and controversial. A number of factors, including a rapid loss of weight, may explain why. But critic Conrad Osborne, who also teaches voice, says Callas lacked the proper technique to sustain her ambitious repertoire, which contained the seeds of her vocal decline.

She was suffering from dermatomyositis, an autoimmune disease that causes muscle weakness, and to an extent, affects the central nervous system. It explains the mysterious ailments that first appeared in the early 1950s and was the reason she lost control of her voice. Professor Mario Giacovazzo diagnosed the disease in 1975, two years before Callas's death, but she did not die of it.

Her great weight loss (80 pounds), which she achieved in 1953 and '54, is controversial. Many think that this affected her singing for the worse; many think it made no difference at all (vocally); some think it helped her, overall. In videos of Callas after the weight loss, you can see her singing with her arms crossed, as if seeking something to push off of, asking, 'Where is the previous substance?'

When a singer loses large amounts of fat, the diaphragm can now descend and flatten, possibly for the very first time. If the singer does not make a conscious effort to continue singing on empty, the lungs overload with air and the exact opposite symptoms occur: The brain automatically loosens the vocal cords to vent the excess air, so that despite the fact that there is actually more air in the lungs, the singer has the sensation of 'not having enough breath' because the air is being blown through the cords fast and hard. The sound waves are now diffused and unfocused, the cords are doming up and the singer loses power, resonance, extremes of range, stamina and accuracy of intonation. My guess is that this is probably what happened to Maria Callas.

The Callas Conundrum is this: what happened to this great singer? What did others say about her decline? Were there warning signs of this decline in her youth? I’ll attempt to cover a wide base of information with clips and videos discussing her voice and artistry to understand this complex vocal decline.

Musicological debate on Maria Callas's vocal decline in the 1950s and 1960s attributes it to multiple factors including weight loss, technical issues, repertoire choices, and inherent vocal instabilities, with no consensus; sources like opera critics and vocal pedagogues often cite her dramatic weight loss around 1954-1955 as a contributing but not sole cause.

Callas was known for her intense need for rest to recover her voice, a habit that regulates the hormones governing hunger (ghrelin and leptin), suggesting the physical and vocal demands of her career were interconnected with her weight management.

It was about protein-pacing—ensuring that every time she sat down to eat, she was giving her body the amino acids necessary to preserve her vocal muscles and maintain her voice quality during the weight loss process, suggesting that proper nutritional management could have mitigated vocal decline.

Callas herself insisted that she never lost her voice, stating in a conversation with Peter Dadzi shortly before she passed away that her vocal cords were still in perfect condition. She said, 'My vocal cords were and still are in excellent condition, but my 'sound boxes' have not been working well.'

Is it not a strange coincidence that this deterioration of the voice began around the time she commenced her famous diet in 1953... Her voice had been deteriorating since 1953. For example, if we listen to the performances which she gave in Mexico City 1950-52 (or earlier), we can hear, among other things, that the voice possesses a magnificent head resonance which she was quick to lose.

When Callas lost all that weight, which took about a year and a half, it had nothing to do with the decline of her voice. Some doctors in Milan diagnosed her as having dermatomyositis, a disease where one loses muscle tone, especially in the larynx. The author argues that the weight loss itself was not the cause of vocal decline, and that maintaining the weight loss on top of her heavy travelling schedule was exceptionally difficult.