Duly is defined as at the right time or as expected. An example of duly is a person showing up when they were supposed to arrive. in a due manner; specif., 1  as due; rightfully.  when due; at the right time.
If you eat a high-fat meal, you will feel tired after eating because fat is harder for the body to digest than carbohydrates and protein. When you eat a lot of fat, your digestive system becomes sluggish, and your body sends more blood to your digestive organs so that the job of digesting your food can be done.ood Allergies. A classic symptom of food allergies is feeling tired after eating a food you are allergic too. Common food allergies include gluten (the protein in wheat), dairy products and tree nuts, but sensitivity to any food can cause fatigue.
I am 25 year old American male, living in Tokyo. Occasionally I feel very weak after eating. This began last December with absolutely no problems like it before that. The weakness is a severe physical weakness and mental blur as if all the energy has been sucked out of my body. It usually occurs 1-2 hours after eating, but it has happened immediately after eating and up to 5 hours after eating.