What kind of diet works best? Low fat diet? Low carb diet? Do total calories matter?
The most popular theory right now is that carbs increase weight gain because carbs stimulate insulin, which is a hormone that causes our liver to convert carbs into fat, so reducing carbs will help you lose weight.
But, there are populations of people that eat high carb diets and are still lean and not over weight, example, Japanese populations eat a lot of rice, which is a refined carbohydrate, it is high on the glycemic index, yet these populations are not over weight. Likewise, there are populations that eat high fat diets that are lean as well.
People lose weight on low carb AND low fat diets. Why?
Because they are eating overall fewer calories AND they are cutting out the worst foods that are high in calories, low in nutrients, and highly rewarding….which are foods that are high in BOTH carbs and fat which are things like: donuts, cake, pie, muffins, pizza, hot dogs, burgers, pastry, cookies, ice-cream, anything deep fried, potato chips, french fries, anything breaded and fried….you get the idea.
The yummier something is, the more we are going to eat. And not just because it tastes good, it actually causes a physiological effect in our brain that increases our satiety level, meaning we will need to eat more to feel full!
When we eat foods that are high in both carbs (starch or sugar) AND fat then we produce dopamine, that neurotransmitter that gives us the reward feeling. The more dopamine a food makes you release (the yummier it is), the more of that food you will want to eat. Food companies know all about this and make processed and packaged foods so dopamine-stimulating that you will want to keep buying their product.
So the simple answer to losing weight is to eat fewer calories, the hard part is doing that without feeling hungry or fighting off cravings. If you feel good on a low fat or low carb diet then by all means stick to it.
Another option can also be to have moderate portions of all macronutrients (fat, protein, and carbs) in the form of whole foods, having variety ensures that you get as many nutrients as your cells need to function optimally – meats, veggies, nuts, seeds, beans, fruit, whole grains, eggs, etc, all contain everything we need. When you eat whole foods and not crap (my personal favorite diet is the “Don’t eat crap” diet ;)), then you won’t get the dopamine surges that make you eat more calories than you need, and your cravings for crappy junk food will go away once your dopamine levels stabilize (about 2 weeks).
Lastly, another factor that makes us feel full and satisfied is how physically full our stomach is, so eating whole foods that are high in fiber will make you feel full without being high in calories. High fiber foods include all of the fibrous vegetables like broccoli, cauliflower, Spinach and other leafy greens, peppers, etc., fruits, beans and legumes, whole grains, and nuts and seeds.