In my sport nutrition practice, I often hear this response from athletes.
While the monotony and repetition can help with meal planning, there are two main concerns. The first is lack of nutrient variety and the second is not adjusting your diet to meet the demands of your training. If you stick to a limited food selection, you are likely missing out on essential vitamins and minerals found in different food groups.
If you aren't systematically altering your macronutrient intake to support higher volume and/or more intense training sessions, you may be in a constant state of low energy availability.
By strategically adjusting your meals and snacks, you can better support your training by providing your body with a full spectrum of nutrients and energy to support proper muscle function, immune system support and bone health while reducing the risk for nutrient deficiencies, fatigue and injury.