You may be making a mistake in your diet, concentrating only on the main macronutrients like protein, carbohydrates, and fats. You may be even calculating calories, and still making a mistake by ignoring something very important: the fiber content of the food items and the vitamins. Somehow everybody heard already about vitamins, you could have some sort of vague conception that you need them, but what I often observe being utterly ignored is the fiber content. Nobody really cares about fiber. Many of us don t even know what that might be, in which food items can you find them, and the ultimate question: why the heck you need that at all?
Why do you need fiber?
For a smooth digestive system. Why you need that? Because in order to stay fit and sexy must have a smooth-operating digestive system. You need fiber because also cleans very efficiently your organism from the waste. Must admit, I myself albeit I do have knowledge about fiber, even deep down in my unconscious mind know about the fact, that we need it, I utterly ignored it, always focusing on macros and calorie intake, till the moment I got a pretty serious health issue with my digestive system and related organs. The doctor asked me: “do you consume enough of fiber?” I stood there and blinked. "No, not really." Actually, as I calculated my meals I found out, that the probable quantity I was ingesting was no more than 10-15 g. Nevertheless, the general view on the topic is, women should consume around 25 g and men 50 g daily. In my special case, the doctor advised 45 g of fiber. Below I will enumerate some food items rich in fiber content, so you don't have to grope in the dark and do guess work. 
I took immediate action: revised my whole meal plan, step-by-step introducing a lot of fruits and vegetables, getting my daily fiber intake around the mentioned value, staying consistent to that, month after month and guess what! The problem disappeared, avoiding a very probable operation. Avoid though getting from 10 g of fiber immediately to 30 g because bloating will occur and you might face some discomfort. Change must be made bit by bit, allowing time for your organism to get used to it. Because the fibers will put your digestive system to work! pay also attention to drinking at least 8 glasses of water a day. The extra digestive work needs the proper hydration. 
Do not make the same mistake as I did and always watch out to consume enough fiber that will facilitate all those digestive processes, before any problem occurs. Fibers sweep your organism; they are proved to be effective in preventing many illnesses, including some types of cancer as well as banal constipation. They can lower cholesterol and improve overall digestion. 
And now, foods high in fiber, here we go:
Whole grain products, like, cereals, bread or even crackers
Oats
Fresh fruits, like raspberries, blackberries, apples, pears, bananas, blueberries. Don't peel the apple and the pear! It is there for a reason! 
Every vegetable rules when it comes to fiber: broccoli, cauliflower, spinach, artichoke, potatoes, cabbage, corn etc. 
Legumes: Beans, peas, lentils. 
Dried fruits are also high in fiber. A handful of dried fruits, like prunes, figs, dates, raisins, dried apricots over your morning cereal could be a tasty and very effective high fiber combination. Extremely good choice as a start off. 
Nuts, seeds, they might be loaded with calories in comparison to vegetables, but a handful taken as an afternoon snack won't do any harm to your silhouette, believe me.

Do you think you consume enough fiber? Load a calorie counting app, like Fat Secret, or any other, introduce what you have eaten and find out. Make a new plan or adjust! Don't wait till it is too late, we tend to ignore things that are functioning good, but our body needs constant attention to stay that way!