Is it really unhealthy to eat food late at night?

People should eat meals based on their wake/sleep cycle. If your husband works 3-11.30pm, then his dinner may be eaten after 11.30pm, assuming he stays up for another four hours. If he goes to bed soon after arriving home, then he should eat his dinner at 7pm. 

There is nothing special about stopping eating by 7pm because it’s the calories you eat minus the calories you burn in activities that decides your weight. 
That said, the later you eat, the longer it’s probably been since your last meal. So you’re likely famished and prone to overeating.

The other thing is, when your stomach is full, it’s harder to sleep soundly. Your body digests any food eaten whenever it is eaten. When food enters your mouth, digestive enzymes are stimulated in your mouth and stomach. It doesn’t matter what time you eat even the smell of food stimulates the production of digestive juices in your mouth. 

Bran is the brown, outer covering of cereal grains such as wheat, rye, oats, barley, corn and rice. As it goes through your gastrointestinal system, it absorbs water and swells. Any food that is undigested is excreted, as are other waste products.

There are two types of fibre: insoluble and soluble. Insoluble fibre is effective at increasing stool size and bulk and helps reduce constipation and haemorrhoids. Insoluble fibre includes wheat bran, whole cereal grains and vegetables. 
On the other hand, soluble fibre forms a gelatin-like substance in the intestines and increases the water content in your stool. Soluble fibre is found in citrus fruit, legumes (dried beans and peas), oats, barley and gums, which are found in oatmeal and dried beans.

Researchers have suggested that soluble fibre decreases blood cholesterol and results in a lower blood sugar after meals for diabetics.