What is Health?
Merriam-Webster dictionary defines health as:
It's interesting to notice that within the various definitions above, some instances use the solitary word "health" to infer a positive state or condition of the body, mind and spirit such as in the example of "nursed them back to health." The other description within the same numbered general definition then delineates the idea of "poor" health and "good" health. For the sake of simplicity and consistency, we will use the term of healthy to describe a body, mind and spirit which is operating well and without disease. We will also use the term to describe foods and activities which may contribute positively to maintaining that healthy state as previously described or help an individual transition from a state of being not healthy, to healthy.
Big Ocean
Healthy foods, healthy exercise programs and all types of health advice fill millions if not billions of web pages, books and magazines. Restaurants have healthy menus and grocery stores sell "organic" food as a healthy alternative to, well, non-organic. 
It's a big ocean of healthy and unhealthy choices out there; what are the right and wrong choices and how can we know? Unfortunately, there are so many complex interactions involved within the body and between the body and the outside world, that answering that seemingly simple question with 100% certainty is usually not attainable. The good news is that there is a body of evidence and history in different areas of health related topics, that we can at least increase the odds of being and staying relatively healthy throughout much of life. Most of you are already quite familiar with the health topics of nutrition and exercise so we'll begin there, but simplicity is the order of the day.
Nutrition
This could actually be considered somewhat of a controversial subject and over the years, some highly publicized research has contributed to skepticism regarding healthy versus unhealthy foods. 
Egg consumption has been a controversial topic with regard its contributing factor in elevating blood cholesterol and increasing the risks of coronary heart disease (CHD) and stroke. Rong et al. (2013) wrote that the results of their research do not support elevated risks of CHD and stroke from higher egg consumptions. However for years, eggs were deemed very unhealthy due to early research indicating high incidents of stroke and vascular disease associated with high cholesterol from eggs. As more accurate research came out with findings to the contrary, people may have developed a bias toward not believing studies regarding what is and is not healthy. This just emphasizes that each of us might want to be cautious at the very least, when making determinations as to what is and is not healthy to put into our bodies. Following are some suggestions for you to research and consider.
Supplements
Busy lifestyles have changed the face of "traditional" mealtimes for may people. If balanced meals are difficult to come by, supplements may help to fill in the deficiencies that may be present.
Numerous studies have been performed on the effects of fish oil on various systems of the human body. Couet et al. (1997) summarized in their study that "...6 grams per day substitution of visible fat by fish oil over three weeks in healthy adults reduces body fat-mass and increases basal lipid oxidation."
Care, however must be taken when adding supplements to the diet. Overdose can occur if too may supplements are ingested. For example, the vitamins A,D,E and K are called "fat soluble" while vitamin C is "water soluble". The fat soluble vitamins can store and accumulate in the body to higher than normal levels and potentially cause harm to the body. Water soluble vitamins like C will be excreted in the urine if levels increase higher than needed in the body (however, one should still be aware of acceptable levels for the body with any item ingested).
Altering the vitamin and mineral content of the body with supplements should be discussed with your physician to also ensure there are no potential allergic reactions to items taken. For instance, there are many people who have allergies to nickel which may cause severe rashes. Most vitamin/mineral supplements contain nickel and may cause an adverse reaction. While these supplements can be obtained over the counter, the potential to cause bodily harm cannot be dismissed and discussions with a physician before adopting a supplement regimen is highly recommended .
Key Times of the Day
BREAKFAST
While the importance of what you eat cannot be overemphasized, neither can the idea of when you eat. If you sleep between 6 to 8 hours a night, remember that unless you sleep walk into the kitchen and fix yourself a meal, your body has just gone that amount of time without eating. Yes, your metabolism does slow down, so it's an apples to oranges comparison with regard to the amount of food intake your body needs during sleep compared to waking hours, but it is still quite an extended period without supplying food.
Late Night (before sleeping)
Just as important to consider is the time before sleeping. Loading up on food before going to sleep for several hours allows that food to potentially store as fat since, as mentioned earlier, the body metabolism slows which may not allow your body to process or "burn" the food you just ate. This may lead to additional adipose tissue and increased risk for negative health factors such as coronary heart disease and diabetes.
Portions
There are plenty of people out there willing to tell you what to eat and what not to eat. You can certainly make those decisions based on what you like and don't like without too much fuss if you simply watch the portions. Denying yourself ice cream if you absolutely love ice cream almost more than life itself may lead to binge eating of ice cream if you give in at some point in the future. However, satisfying the craving with
a small cup instead of eating the gallon at one sitting, may work to satisfy the crave, but not overload the calories. Yes it may take a bit of self-control, but it could keep away the binges. Keeping the portion sizes of all meals relatively small may allow you to maintain or achieve a healthy weight with less adipose tissue and thus a potentially lower risk of disease related to higher body fat.
Exercise
Just as with nutrition, a world of information is available related to specific exercise programs designed to fit the likes of many different people. Given all the variation is types of exercise, one very simple formula (three variations) generally holds true in relation to nutrition, exercise and health:
If
Calories taken into the body = Calories burned
Then you maintain your overall weight
If
Calories taken into the body < Calories burned
Then you generally lose weight (fat)
If
Calories taken into the body > Calories burned
Then you generally gain weight (fat)
This may seem like oversimplifying a complex physiological process, but it is simply to give a high view of what needs to be done to achieve certain results. Most foods have calorie information (even fast food restaurants) so tracking an approximate input can be accomplished. Burning calories might be a little more difficult. Fortunately, there are many different types of body metric trackers on the market which can monitor your calorie burn as well as your caloric intake by allowing you to enter data into it like food and drink consumed. Many can then follow the movements of your exercise and calculate approximate calories burned.
Well what type of exercise is the best? The best is the one you will do. This will most likely be the one (or more) you enjoy doing. 
If you try and force yourself to run long distances because you see so many people achieving great results and fat loss this way, but you absolutely hate running long distances, chances are you will stop running and maybe stop exercising due to the failure. Now conversely, you may just find that you really love running after giving it a try and that's excellent as well. It is just that it may be beneficial to at least begin with something you enjoy doing to achieve some success right from the start.
Exercise Types
There are aerobic and anaerobic exercises. This delineation is not really an all or nothing such that anaerobic exercises have some aerobic quality and vice versa.
Aerobic exercises will predominantly burn fat and tone muscle while anaerobic exercises will generally build muscle and burn less fat.
Aerobic exercises like running and bicycle riding should be done for more more than 20 minutes approximately. 
The main reason for this is glycogen. Glycogen is a sugar reserve in the muscles which is easy for the body to get to and use for energy. This is used up first for energy in the first (again approximately since everyone's body metabolism is lightly different) 20 minutes or more of continuous aerobic exercise. Once the glycogen reserves are used up, the body then starts to hit the fat reserves for energy. This is when the body fat reduction begins. For those who cannot tolerate intense actions like running, walking for extended periods of time is excellent as well and burns the calories.
Anaerobic exercises such as weight lifting, build and shape muscle through relatively short bursts of energy with rests in between. 
Since the movements do not continue for continuous 20 minutes or more, the burning of fat is much less than during aerobic exercise.
Generally, a combination of the two types of exercises are beneficial such that aerobic exercises helps to increase blood flow, oxygen flow and increase the efficiency of the heart as well as burn higher levels of fat. 
Anaerobic exercise like weight lifting not only shapes and strengthens the muscles and tendons, but additionally strengthens the underlying bones by stimulating the body to increase the bone density as heavy stresses are put on them. An additional little benefit from carrying muscle with a bit larger size than you may have had before lifting weights.....even when just sitting, larger muscles burn more energy than smaller muscles.