Muscle gain in deficit
An interesting and controversial topic. Is it possible to build muscle in a calorie deficit?
Yes, it's possible, as both practice and research support it. It's called recomposition. Here's a comprehensive review of research on the topic (DOI: 10.1519/SSC.0000000000000584)
Quote:
"While many assume this only occurs in untrained/beginners and overweight/obese individuals, there is a significant body of literature demonstrating this body recomposition phenomenon in resistance-trained individuals."
But. There are many nuances, and recomposition isn't accessible to everyone, and not always. For example, the degree of calorie deficit greatly influences recomposition. In this study, a calorie deficit of more than 500 kcal/day completely halted muscle growth.
(PMID: 34623696). More details on the nuances in a post on my Telegram channel.
If you have little training experience and a lot of body fat, you don't need to eat even more to build muscle.
Body fat is excess energy that can be used for muscle growth.
And if you have a lot of fat, you probably don't need to eat even more to build muscle.
Do anabolism and catabolism occur simultaneously? Of course they do. The question is which is more prevalent and in which tissues.
For example, you can stimulate anabolism in muscle tissue through training and consuming sufficient protein while being in a calorie deficit and burning fat simultaneously.
And wounds and bones heal in a calorie deficit, which is also anabolism. Yes, it's worse than without a deficit, but still.