First of all, there are some myths present that cripple a lot of attempts to get into shape. Before we start addressing the question itself, those myths have to be busted.
- Myth 1: Weight loss
- Myth 2: Spot reduction
- Myth 3: All you need is exercise
- Myth 4: All you need is a diet
- Myth 5: Doing crunches helps you develop a 6-pack
The first big trap is hidden in semantics. People often ask how they can lose weight, they weigh themselves and celebrate every kilogram they lose. The problem is that they don't really want to lose weight - they want to lose fat! Losing water and/or muscle mass does not help them achieve their goal - looking good. There are many diets that help you lose a lot of weight fast - but not the kind of weight you want to lose! That's why you have to check if you are losing weight healthily. Besides weighing yourself, check your waist, thigh, chest and neck measurements, or use some other of measuring your Body Fat Percentage (BF%). If you gain weight, but drop in BF%, everything is good!
is a myth. Many people ask questions about losing fat in some particular body parts, for example the belly or chest. The problem is, you can't really lose fat from a particular spot - you just lose fat and your body decides where to use it up first. Be patient and reduce your BF%, and at some point you will lose those manboobs and belly!
All you need is exercise
People believe that once they start exercising, they will be able to lose fat while stuffing fast foods down their throats. Sadly, that's not the case. Let’s do some math: intense swimming for two hours could let you burn around 800 kCal, as a rough estimate. After such a hardcore training session you would feel entitled to reward yourself, right? I'm guessing that you'd drink a 500ml sports drink and perhaps treat yourself to a pizza or spaghetti? Oooops! You have just undone all your efforts! You ate almost as much as you burnt exercising! The truth is, it's very hard to outrun your fridge - if you eat badly, you won’t be able to make up for it just by exercising. You need to change your eating patterns!
All you need is a diet
Taking that into account, many people believe that a diet is a solution to their problems. Sadly, it isn't. The problem is in the very definition of a diet - at some point in time, it ends, and once it ends, you will bounce back to your old weight, or even higher! That's the famous yo-yo effect. Keeping the weight down can be harder than getting it there! So, how do you avoid it? Don't impose a diet on yourself - you won't keep it forever. Make gradual changes to your lifestyle. Nothing radical, just change one thing every week or third day. Make smart decisions, and think about what you eat. Pick a whole grain pasta and bread over the regular ones. Pick brown rice instead of white. You don't have to give up all your pleasures or favorite foods - sooner or later you'd crack (or live a sad life with no chocolate in it!). Just be sure to think and make decisions, instead of mindlessly stuffing things down your throat. You can read about healthy eating habits later on. For now - just remember that a diet isn't an answer!
The 6 pack
There is one more popular misconception. People think they have to do sickening amounts of crunches to get the abs they dream of. Actually, that's not the case. The most important thing about visible abdominal muscles is having a low Body Fat percentage. No matter how big muscles you have, they will be covered by fat if your BF% exceeds 20%. Abs are visible around 15 BF% for men (a bit more for women, as they naturally store fat on some body parts). Also, it’s good to know that many exercises that supposedly strengthen your abs actually target your hip flexors and/or are bad for your back. So don't worry about crunches, just focus on lowering your BF%, it should be enough, and if it isn't, we will worry about it once we are there.
SO WHAT DO I DO?
Now that we dealt with the popular myths we can get to the actual process of losing weight.
First of all, you should be changing them gradually, in a controlled manner. Your new habits must have the time to actually become habits. They also need to be sustainable - it's a lifestyle change, not a temporary diet! The second important aspect is to stay positive. Studies show that a negative dieting pattern, the route of "guilt", results in lower success/failure ratio and has a lower percentage of people who were able to maintain their weight after the weight loss. If you feel the urge to eat those donuts and then feel guilty about it, you're doing it wrong. You’re eating patterns don't need a revolution - they are a sum of small decisions. Having a pizza or a beer on a Friday night out isn't necessarily a good decision, but it’s still just a single one. It’s the overall that matters.
Energy intake and expenditure
Why do we get fat? Because we eat more energy than we use up - we overeat. If you eat less than you need, you are going to lose weight, if you overeat, you get fat. But this isn't all that there is to it. First of all, notice what I wrote - if you don't eat enough, you lose weight - not necessarily fat! Also, there is the big question - why and how do we overeat?
How much should we eat? I can’t give a definite answer to that question, as it varies from person to person. We all have different Basal Metabolic Rate (BMR) defining how much energy we expend just to stay alive. To that we have to add our energy expenditure. It varies from person to person. It’s actually very hard to accurately measure one's BMR or energy expenditure - while 1h of cycling may mean burning of 300kcal for one person, another might burn only 250. Actually, we can never be sure how much energy we ingest, too! How much of the macronutrients is disposed of by the body with feces? How effectively one’s body uses certain macronutrients? It’s very hard to tell. That’s why I don’t encourage you to do the "calorie counting". Your calculations can be wildly inaccurate, and I personally think it’s a bit of a chore, not in line with the things I wrote earlier on changing your lifestyle.
While how much we eat is a very important and decides if we gain or lose weight, what we eat decides how hungry we are, whether we burn fat or muscle, and how effectively do we do that. Some foods bump up our calorie count without leaving us full. Some make us feel hungry a few hours after eating them. Some foods put our bodies into "energy storage mode" while others let us be energetic for long periods of time. So while people will say "the only thing important is how much you eat", you should know better - what you eat matters, and also influences how much you eat!
The three macronutrients
I’m sure you know what the three macronutrients are - protein, carbohydrates and fats. There are different strategies in planning the balance between the three in your diet. Some people tend to react better to low fat, mid-high carb intake, others do well with low carb, medium fat diets. My body responds well to cutting down on carbs, and I've lost 20kg over half a year by gradually changing my eating habits and eliminating a lot of carbohydrates. You will have to try and see what works for you. Still, there are some concepts that are uniform to nearly all the diets.
One of them is this: you need protein. When losing weight, you will be in a caloric deficit. Eating enough protein (around 0.8 - 2g of protein per 1kg of body mass daily) and physical activity are the two most important factors helping your body in losing fat instead of muscle. Proteins are the building blocks for muscle. They are broken up into necessary amino-acids by your body. Some of the necessary amino acids can be synthesized by our bodies, but some need to be ingested - so remember to eat your meat/dairy/soy/eggs/whatever.
Insulin and GI
Another important concept is the Glycemic Index (GI) of the foods you eat and its effect on your insulin levels. Basically, the glycemic index depicts how fast the food will be turned into sugar in your bloodstream after ingestion. A low GI means that the food is processed slowly and it rises your blood sugar levels slowly. Those are the good products, leaving you with a steady supply of energy. A high glycemic index is means trouble. It rises your blood sugar levels high and fast, forcing your body to release more insulin to your bloodstream.
Insulin is the single most important hormone responsible for fat management in the human body. It has a few tasks - it lowers the blood sugar levels, forcing the sugar to your cells as an energy source. It also causes your body to store fat. If your blood sugar levels stay reasonable, everything is fine and the insulin does its job. If your sugar levels are too high, the body can't process all of the sugar, so the unused energy gets converted to fat by your liver and then is stored in your body due to the presence of insulin. A chronic exposition to very high blood sugar levels may cause your cells to build up partial insulin tolerance - if so, they need a lot more insulin to properly digest sugar and turn it into energy. Those high insulin levels help you store more fat.
Usually, the more processed the food, the higher its GI is. That’s why we prefer brown rice, full grain products, fresh carrots instead of boiled ones etc. Products containing lots of sugar, especially refined one, are sure to raise your blood sugar level fast and high. You can check GI tables on the internet to get a feeling for what’s good for you and what’s bad. Remember to check how much sugar a product has - a watermelon may have a high GI, but is has little calories, so you can eat it safely! Read a bit about the topic and start making informed decisions on what you eat. Also - try not to drink your food. Coke, fruit juice, sports drinks and the like - they all have lots of sugar, but don’t leave you with the feeling of being full!
Drink water, lots of it. It is necessary for your kidneys to process the protein you eat, and it’s necessary for the process of burning fat. Drink even if you’re not feeling thirsty - sometimes you can be dehydrated and not feel thirsty at all! Also, sometimes we think we are hungry, while actually we are thirsty!
So, we finally got here! Exercise! But wait a minute... Didn’t I write earlier that exercise isn’t the best way to create a caloric deficit? Yes I did! But we are not exercising to create a caloric deficit - we are exercising to prevent our bodies from eating up our muscles once we are in the caloric deficit.
That’s why I don’t actually recommend doing cardio and aerobic exercises that are typically prescribed for weight loss. Now don’t get me wrong - cardio is great in a lot of ways, and if you have the time and desire, go ahead and do some cardio! But it is a good idea not to limit yourself only to low intensity activities. In order to trigger the muscle preservation & growth reaction of your body, you need some high intensity stimulus. You could lift some weights or do some HIIT training. Basically - do something you enjoy!
One more thing - if you don’t want to do weight lifting because you’re scared of turning into a Hulk, don’t worry. It takes a very specialized diet and years of specialized training to get that big. It does not just "happen" as a byproduct of training!
THIS IS JUST A STARTING POINT
It is impossible to cover the whole fat-loss topic in this answer, as there is a lot of research to be done in the field, and hundreds of books have been written about it already. Hopefully this answer will give you an idea on how to lose weight and what to look for when educating yourself further. Remember - it’s not only working about hard, but also working smart!