You might have heard that a calorie is a calorie, and that might be true on some level. There have even been experiments to test this theory. For example, the all Twinkie diet was one where a man ate nothing but Twinkies, Oreos, and other junk food, but ate within his calorie limits and lost 27 pounds in 10 weeks – “proving” a calorie is a calorie. Can this really be true?
First Law of Thermodynamics
The first law of thermodynamics basically states that energy (calories) can neither be created nor destroyed. It means that energy in equals energy out. In other words, you will lose weight as long as you burn more calories than you consume over a period of time. This is not a theory. This is fact – a law of chemistry.
Based on this first law of thermodynamics then, you should be able to eat whatever you want and still lose weight as long as you stayed within your calorie limits. While I have never tested this “theory” over months, I can tell you that it is true – you will lose weight; however, your fat loss will not be the same as a healthy diet. Weight loss and fat loss are not the same thing. I’m sorry if I just burst your bubble.
All Calories are Not Created Equal
There are studies all over the place that show how weight loss was the same whether the individual ate a junk food diet or a healthy diet, as long as the calories were the same. However, none of these studies measured body fat levels, hormones, or the general effects on their health – like cholesterol, triglycerides, or even mental health.
I include mental health because even though you could lose weight eating junk food, it is not as easy as you might think to eat so few calories with such calorie dense junk food. These foods will give you a quick “high” as you feed your cravings, and then you will be starving until your next “meal”. Junk food makes it harder to lose weight on every level.
The Technical Truth
A calorie is a calorie on a purely chemistry level. However, a calorie is just a measurement of energy – it does not take into account the nutritional profile of food, and the dynamic effects it has on your metabolism.
A Twinkie will have almost zero nutritional value, while a chicken breast with broccoli and some fish oil will be packed with protein, essential fatty acids, and all kinds of vitamins and minerals – even though they will have roughly the same calorie content. This difference will affect your body composition, your rate of fat loss, your hormones, and many other metabolism influencing functions.
So yes, you can lose weight eating anything you want. However, you can’t always lose fat eating anything you want, and you’ll be sacrificing your health for a “better” external appearance. Fat loss occurs when you mix the right macronutrients, eaten at the right time, in the correct amounts, with enough vitamins and minerals.
There are no shortcuts to fat loss. It takes hard work. If you are only concerned about losing weight, and have no concerns about losing that muscle you worked so hard for, or the negative effects on your health, then go ahead and eat whatever you want. However, if your goal is to be healthy, lower your body fat, hold onto your muscle, and improve your mental well-being, then make sure your diet is 90% real food – not fake man-made “products”.