maybe, but remember that any food source, whether from fats, carbs or protein, if surplus to current requirements, will be stored as fat.
I would suggest that what is at play here also are the vast differences between your son and you in terms of age, sex and activity type and level. It is unfair but male bodies are more genetically programmed than ours to build muscle, not fat. If he is doing a considerable amount of weight training, this double protein ration is indeed feeding his muscle. But would it do the same for you? Who knows. Female bodies heading towards or post menopause are programmed to store more fat, no matter what you do. Regular exercise combats that and keeps it in check probably better than avoiding carbs after 6pm.
If you workout in the mornings, I would suggest keeping your carbs in the evening because they will store as glycogen in your muscles to fuel the next day's workout. The stored glycogen is always used first as energy supply. Without it you will get tired sooner during your workout.
A sensible ratio of 40-30-30 is better than avoiding certain food groups I reckon. Fish with several servings of vegetables would be ideal. And don't forget that there is protein too in rice and noodles. What's wromg with a potato? If you make it sweet potato you get a mega dose of vit A too. Concentrate on balance in all things to cover all food groups for optimal health, that and adding muscle which burns more calories whether from carbs or protein.
Clare