One of the most common myths you will hear come from the fitness industry, with regards to nutrition, is that eating carbs at night is one of the worst things you can do with your diet.
But is this the case? Are carbs really that bad to eat at night, or is this another myth to put under the bro-science tag?
How many times have you heard people say that they cut out carbs at night and lost a load of weight. Probably quite a few. But did they lose the weight due to cutting out carbs, as carbs are evil, or did cutting out carbs put them in a calorie deficit?
What does science say about this?
Here’s the myth as you have probably heard it…
‘Don’t eat carbs after 6pm. You don’t need them.
Your metabolism slows down in the evening,
so you will just store them all as fat’
Now I’m not sure where 6pm came from, or who came up with this magic number, but it seems to have stuck. Either way the timing is a moot point. Lets start breaking this myth down by tackling metabolism first.
This study (1) shows that even though your metabolic rate drops below your BMR (basal metabolic rate) during sleep, the actual overnight metabolic rate, that’s the energy expended during the night, and BMR are equivalent. So to put it simply, the amount of calories you burn during sleep is no different to the amount of calories you burn during the day whilst resting.
But, what if you train on a regular basis. Does that have any effect on your metabolism?
It appears to. Research (2) also shows that after a period of prolonged exercise the overnight metabolic rate actually increases, whilst also enhancing lipid oxidation, or your fat burning ability. So you could say that if you train, not only does your metabolic rate not slow down during sleep, it actually increases.
I think we can safely assume that your metabolism is definitely not a reason to not eat carbs at night.
So next up lets talk about the actual eating of carbs in the evening. Whether it’s after 6pm, 7pm or 9pm. It really makes absolutely no scientific difference.
A 6-month study by researchers in 2011 (3) examined the effects of a low calorie diet based on carbs eaten mostly in the evening, versus, a low calorie diet based on carbs eaten throughout the day. The macronutrient breakdown was the same for both groups (20% protein, 30-35% fat, 45-50% carbohydrates). The results showed reductions in weight loss, BMI, abdominal measurement and body fat percentage across both groups. Not really a surprising result. Although there was a slightly greater reduction in body fat percentage found in the group that…..yes you guessed it…..
Ate carbs in the evening!
Not only did this group lose more body fat, they also declared greater feelings of fullness throughout the study length, whilst also seeing favourable adjustments to their glucose balance, insulin resistance, and lipid profiles.
Therefor we could summarise that it’s clear that eating carbs in the evening will not directly make you fat. Carbs aren’t the villain. So what is?
If you find yourself putting on weight a better place to start would be to look at your calorie intake vs expenditure. Be more mindful about what you eat, and adhere to any diet you decide to try.
So repeat after me…
‘Carbs are not my enemy, excess calories are!’
REFERENCES
1. Seale JL, Conway JM. Relationship between overnight energy expenditure and BMR measured in a room-sized calorimeter. European Journal of Clinical Nutrition, 1999. 53, 107-111.
2. Mischler I, Vermorel M, Montaurier C, Maunier R, Pialoux V, Péquignat JM, Cottet-Emard JM, Coudert J, Fellman N. Prolonged daytime exercise repeated over 4 days increases sleeping heart rate and metabolic rate. Canadian Journal of Applied Physiology, 2003. 28(4):616-629.
3. Sofer S, Eliraz A, Kaplan S, Voet H, Fink G, Kima T, Madar Z. Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner. Obesity Journal, 2011. 19, 2006-2014.