Another theme is perseverance. Changing from an unfit to a fit state, whether it's physical or mental, is not easy. The characters usually face many obstacles. In these novels, they have to keep pushing forward despite difficulties, which shows the theme of perseverance. For example, they might face mockery from others for their initial state or struggle with the hard work required for the transformation.
I'm not sure of a specific 'fat to fit' light novel that is extremely well - known in this regard. However, some light novels that deal with self - improvement themes might fit the bill. For example, 'Sword Art Online'. The main character Kirito has to constantly improve himself physically and mentally in the virtual world to survive. This can be loosely related to the concept of going from a 'fat' (unprepared, unfit) state to a 'fit' (capable, strong) state.
One common factor is a change in diet. If a person starts consuming more high - calorie, junk foods like fried chicken and sugary drinks, it can lead to weight gain. Another factor could be a decrease in physical activity. For example, if someone who used to exercise regularly stops working out due to a busy schedule or lack of motivation, they are likely to gain weight. Also, hormonal changes can play a role. Some medical conditions that affect hormones can slow down the metabolism, causing the body to store more fat even with the same amount of food intake.
Diet is a key element. People usually had to change their eating habits from junk foods to healthy ones. Exercise is also crucial. Starting small and gradually increasing the intensity helps. Another key is motivation. Without it, they wouldn't have been able to start the journey from fat to fit again.
A common theme is Naruto's enhanced combat abilities due to his fitness. He can execute his moves more precisely and powerfully.
One common theme could be illness. The coughing fit might be a symptom of a more serious disease that the character is dealing with.
Some common themes might include self - acceptance. The characters may struggle with their body image as they are fat and also with their sexual orientation as they are gay. Another could be love and relationships, showing how they navigate romantic connections in a society that might have certain prejudices against both being fat and gay.
Overcoming obstacles is another theme. Like in the story where a fat kid is bullied for being overweight but then finds a way to shine, either through a talent or by being kind. They face the difficulties of being different and rise above them.
One common theme is self - acceptance. Naruto having to deal with being fat means he has to come to terms with his new body image. Another theme could be the reaction of others. His friends and the villagers might have different reactions, from teasing to genuine support. Also, there could be a theme of perseverance. Naruto might try different ways to either lose weight or adapt to his new state while still being a great ninja.
One common theme is body acceptance. The fanfiction often shows the Avengers learning to accept their own or their teammates' new, larger body types.
Discrimination is a common theme. Fat people often face unfair treatment in various aspects of life, like in employment, social settings, and even in the medical field.