Posted by Dayne Hudson in Weight Loss
Estimated reading time: 7mins
The notion here is that by doing cardio on an empty stomach, you'll tap right into fat stores and thus lose weight faster. It sounds possible, but it's not largely supported by science.
The research into this question actually shows the total opposite: a meal before training can give you more energy to perform the exercise! And with more fuel in your tank, the greater your output and potentially, your fat loss results.
This myth may stem from other research that shows cardio in a fasted state can lead directly to more fat burnt. Wait, what?! So fasted cardio is better?
At the end of the day -- no!
Just because more fat loss is burned in a given period of cardio, doesn't mean it's going to be any better at the end of the day. This is because your body is very clever with its various mechanisms for utilising fuel. If you happen to burn more fat in one sector of the day, your body will make up for it by burning a higher amount of carbohydrates in another.
What governs fat loss is eating in a calorie deficit consistently over a long period, and not any additional fat burnt during fasted morning cardio (that your body ultimately evens out at the end of the day anyway). The bottom line is if you like fasted cardio and it doesn't bother you, then do it. But science says: you won't be experiencing superior results.
Such a myth was born out of the marketing headquarters at a large cereal brand. It sold cereal, but it wasn't supported by science!
The truth is, eating first thing in the morning to "kick start" your metabolism isn't correct. Research shows you simply won't burn any more fat.
Another study was done on 283 adults and found no difference between those who ate breakfast and those who abstained.
Again, it comes down to your personal preference: if you enjoy eating breakfast and it fits within your daily macronutrient amount, then keep eating it! But doing so doesn't give you any metabolic advantages.
Can you believe that still in today's day and age with all the research we have -- people still tout this as truth!
It was once thought that the resulting spike in insulin from eating carbohydrates meant the fat-storing tap turned on right away.
But it's not true. Fat is stored simply when you eat more calories than you burn.
Here are some scientific truths:
- When a diet is 77% carbohydrates and tuned to a calorie deficit, these apparent evil surges of insulin make made no difference (8). Weight loss is observed the same as in any other scenario.
- And further to insulin, whether your carbohydrates are low or high GI, it will make no difference to your end fat loss.
Another study examined a diet HIGH in carbohydrates and LOW in carbohydrates but set to a calorie deficit. It would let us know if a high carbohydrate fat loss diet really led to more fat gain. And what did they find? Just like the study in the first bullet point above -- no differences in fat loss! The scientists concluded:
"Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize."
It boils down to this: If you get enough protein and still eat in a calorie deficit -- carbohydrates WILL NOT make you fat! They are critical for energy and your workouts and are too often unfairly vilified!
This is another myth that makes sense in theory but doesn't in research: if you don't "burn off" your ingested carbs they'll turn straight to body fat.
It. Won't. Happen.
Surprisingly, your metabolism actually speeds up when you go to bed. It doesn't get slower. So, you're actually burning more calories whilst you're sleeping, as your body is busy turning over new proteins and recovering.
Further research found that when subjects ate 80% of their carbohydrates at night, they lost more fat and had higher levels of the hormone leptin. You might remember reading about leptin here before; leptin is a hunger regulating hormone. The more you have the less hungry you are.
And if you have trouble sleeping, and/or need any more convincing that consuming carbohydrates is ok later in the day -- let us add that carbohydrates before bed can improve your sleep! This is due to their ability to bolster tryptophan and serotonin, two brain chemicals that facilitate shut-eye.
So don't shy away from carbohydrates before bed; they can serve you well in the right context.
This myth flies in the face of key scientific findings pertaining to protein. Yes, eating less than your body burns is how to lose weight. But we must keep in mind that protein is a vital ally when it comes to fat loss, because:
- It beats out carbohydrates and fat when it comes to keeping you full
- It has just 4 calories per gram, compared to fat's 9 calories per gram (carbohydrates also has 4 calories per gram).
- Your body burns more calories digesting protein than carbohydrates or fat. In fact, it costs 30% of the value of the protein you eat, for your body to digest. So, if you eat 100 calories from protein, you're only, in fact, eating ~70 calories. For fat, that number is a dismal 0-3%, and 5-10% for carbohydrates.
Not convinced? Few gym rats will ever forget the research that overfed resistance-trained subjects 800 calories from whey and casein protein. To be clear about this, they were fed 800 MORE calories than their body burns, via protein. And guess what happened? They didn't gain any weight.
This is simply because not all calories are created equal: it is metabolically costly to digest protein. Scientists refer to this as the thermogenic effect of food.
So, if you're hungry, a lean protein source is terrific at keeping you full, and better at potentially preventing any fat gains. That's why lean protein diets are always recommended for fat loss!
We hope these fat loss myths no longer hold you back and assist you in moving forward with your weight loss goals!