Losing weight

RealGem

Noodles are carbs. Eating all carbs, and nothing else (but a packet of strong flavouring, made up of all synthetic E numbers) will cause you severe health issues in the long run. 

I did this very thing when I had no cooker or microwave for three months in 2011. I just poured boiling water over the noodles for every meal, and I could not understand why I felt lethargic all the time and I was craving carbs and sugar the whole time. 

I honestly attribute this stupid diet to me being pre-diabetic now. 

And I'm sure you know the dangers of being diabetic. 

Please don't do this noodle-only diet!

It's ok to have some noodles. But you need protein and vegetables as well. Better to cut out sugar and have fewer carbs. Eg: have ham, or cheese, or egg, or houmous or bean salad regularly. 

Good luck

Grumpy_chap

Castled said:

Now I'm aware that eating one specific food will lead to a lack of vital vitamins and minerals, however that is not my issue here.  If I was to eat only noodles or rice,  perhaps even pot noodles or similar, would I lose weight?  I am quite active  

This is a terrible idea and it will make you unwell, possibly very unwell or, ultimately, lead to premature death.  To remain healthy, your diet needs to be an appropriate balance of carbs, fats and protein.  The "all carbs" diet that just noodles would be is not a suitable balance.

The answer to the direct question "if I only eat noodles or rice, would I lose weight?" is "it depends".
Weight loss (or gain) is dependent upon calorie deficit (or surplus).
If you eat so much rice and noodles that you are in calorie surplus you will gain weight.  If you eat less so you are in calorie deficit you will lose weight.

If the OP's objective is to lose weight to reach a healthy target and then to manage weight in a healthy band, they could use a tool such as My Fitness Pal.  This is a free app (so MSE) and I use it to great effect.  You can enter your current body data, target weight and track all your food.  The app calculates a suitable total calorie intake based upon the current and target data and also allows you to see the macro (carbs, fats, protein) data for your diet so you can use the tool to manage things quite effectively and achieve a healthy gradual change.