Weight loss is 100% mind over matter.
People will argue the details but it is incredible simply what you must do. The problem is that simple doesn't mean easy. Most people are not mentally strong when it comes to food. They will cheat and they will lie to themselves and they will question the things I say because it won't add up and they won't get the results that they want.
Weight loss is simply a mathematical equation. Every (-)3500 calories is a pound of fat that your body will burn off. The problem is that running at a calorie deficit for long periods of time is very difficult mentally (mostly) but also physically. Time and calories is the equation and people tend to have very little patience for either of those things.
Essentially you need to be brutally honest with yourself about what you are putting into your body each day and you need to be brutally honest with your activity level each day. You cannot lose weight without a calorie negative diet. It will not work. There are things you can do that will help, but going calorie negative is the only way to get your body to burn your fat reserves.
The problem is that going calorie negative alone doesn't work optimally. Your body cannot be allowed to go into starvation mode. If this happens you will slow your metabolic rate, rate of fat burning between meals will fall, and the body's instinct to store fat after meals will be triggered.
So what you need to be doing is:
1. Eat consistently throughout the day. This means you need some kind of food source every 2-3 hours from waking until an hour or so before bed. Going without food for long periods is the worst thing you can do when trying to lose weight. People really fail to understand this. Conventional logic fails when it comes to a body that adapts to it's circumstances. More frequent meals = more consistent metabolic rhythms. Do not starve yourself under any conditions.
2. Hydration is of the utmost importance. Burning calories requires WATER to occur. When you sweat during exercise it is because you are using calories and heat and water are going to be the result of this process. You need to be drinking more water than normal and I would suggest up to a gallon (or more) per day. This is also important because a lot of stored weight is water and just like with (1), the more you drink, the less you will store. Your body is intelligent! Don't starve it of water or you will force it to conserve it and you don't want that for a number of reasons (added weight, less efficient burning of calories, and your body is unable to dump toxins properly).
3. Types of food you put into your body are extremely important. Fiber is a must when you're trying to lose weight. You need your metabolism to be cranked to high gear. Water, fiber, and exercise, will get your GI tract moving and that will slow the rate of absorption of nutrients. You want to have a source of fiber with every meal and you need to find what kinds of fiber work for you. If you are eating some fiber sources with each meal and not having complete bowel movements within several hours, you need to continue trying them. ex. For me, oatmeal is not a good fiber source. It does not work like it does in other people. Almonds, however, and spinach, both work quite well. Each body is different. Fiber is insoluble and without water, can be counter productive and cause blocking. DRINK ENOUGH WATER!
4. Understand your body's metabolic pathways. The human body will always make use of the most readily available and easy to use source of fuel. Order of use goes as follow:
a. Alcohol
b. Fructose
c. Glucose and Dextrose
d. more complex sugars and starches
e. protein
f. fats
Keep in mind, this is in sequence of what is consumed, not in storage. The body will not store alcohol sugars but will break it down for energy before anything else. This is why drinking is killer for weight loss (aside from the fact that wines and beers contain carbs as well and you tend to eat when drinking). It puts a complete halt to the burning of stored fats (and anything you've recently consumed as well). So you really CANNOT DRINK ALCOHOL if you are really wanting to lose weight. Sorry but this point is not arguable. If you want results you need to cut alcohol out for the duration.
5. The rest of that list is also very important. If you are not immediately burning energy, then your body will be using those sugars before anything else. You do not want that. You want your body to go to the reserves over all other options. You also do not want the Insulin that your body produces in response to blood sugar spikes. Insulin is directly responsible for the conversion of sugars into glycogen in the blood, in muscle cells, and in liver cells. You do not want this because you want these glycogen stores EMPTY.
So really, you need to avoid, or minimize as much as possible, the consumption of all sugars. If you are going to eat carbs you should limit it to leafy vegetables, nuts, or, worst case - complex or starchy carbs such as root growing vegetables and oats. Anything that is fruit based or from refined sugars will be a hindrance to a weight loss program. This is why Atkins is successful for short term weight loss (but also very difficult - carbs are a high percentage of any diet and eliminating them is extremely difficult).
This presents challenges as well. Without the presence of carbohydrates, blood, liver, and muscle glycogen levels will drop, and without glycogen, dehydration will be a constant issue. This will cause headaches, fatigue, and slow metabolism. Combat this (and food cravings) by drinking more water.
Conclusion:
Ultimately it becomes about focus. I lost 50 pounds over the past year and over 25 pounds over the past 3 months. I wasn't unhealthy but since I'm no longer focused on being super big and lifting in the way I was before, I decided to get as lean as possible. I made it down to a very low body fat percentage in a very short time period. I did it by following a few simple rules.
1. Eating every 2 hours even if I wasn't hungry.
2. Only eatting carbs from vegitables and rarely eatting carbs from roots.
3. Drinking 1-2 gallons of water per day.
4. Exercising to for atleast one hour per day, 30 minutes of which is hard cardio.
5. Eatting fiber w/ each meal.
6. Sleeping 8-9 hours each night on a regular schedule.
7. NO alcohol
By following this routine, getting adequate rest, but mostly: making my lifestyle all about my goal, I was able to get where I wanted to go. Oh and cheatdays are a myth and are the undoing of any legitimate diet plan. Go big or go home. Cheating throws your body into a metabolic reset and you do not want that. Get your body used to the lean conditions and you will be where you want to be before you know it. Just be reasonable with yourself. I went 3 solid months on no carbs and it was EXTREMELY mentally and physically difficult and I am a very strong willed individual. I could have gone longer (and wanted to, because the results were amazing) but life doesn't always work around a diet plan and you need to be reasonable with yourself when there are things beyond your control (ie, I'm traveling in another continent currently, sticking to my plan would have been impossible).
Set your goals reasonably by setting specific dates, then allowing your body time to adjust to its new shape. Then re-assess and continue (perhaps in new directions). Remember that its all about your goals and what your body/mind are capable of. A six pack physique may not occur in a single window (hell, it may not be what you want). It may take many windows or it could even take a couple years. What is important is that you learn how your body works and learn how to shape your lifestyle, goals, and nutritional requirements together.