In the hierarchy of foods to eat when I'm training for sports and fitness, protein and healthy fats come right at the top, and carbs stay right at the bottom. The less carbs I get in my meal, the better.
I've been asked - "But, DON'T YOU NEED CARBS FOR ENERGY?"
Here's the TLDR answer: No.
The lower limit of dietary carbohydrate compatible with life apparently is zero, provided that adequate amounts of protein and fat are consumed.
Embarking on a low-carb diet is a tough proposition in Singapore where 99% of the offerings at any hawkers are rice, flour, or noodle-based, be it your Hokkien Mee, prata, or chicken rice.
Consequently however, the average Singaporean consumes far more carb-rich foods than they require.
I address a couple of common carbs-related questions, as well as how to switch to a healthier diet and become a fat burner below:
1. What exactly do you mean by carbs?
Carbs is a broad term - I'm referring specifically to simple carbs. These are the type of "bad carbs" you find at a Singapore hawker centre - noodles, rice, kway teow, prata etc.
Complex carbs such as sweet potato, whole-grain bread and brown rice are a different story. These are a "better kind of carb" which release sugar over an extended period of time, rather than cause a sudden spike in your blood sugar.
Image courtesy of ST, May 6, 2016.
Eating bad carbs is equivalent to drinking a can of Coke - fuelling you with empty calories that cause insulin spikes and predispose you to developing diabetes over time.
Amongst other reasons, it's this predilection for "bad carbs" that's caused Singapore to have one of the highest rates of diabetes in the world.
2. What happens when you eat too much carbs?
Carbs promote weight gain because it increases the secretion of insulin from your pancreas.
Insulin is a fat-creating hormone - it encourages the deposition of body fat (and the manufacture of cholesterol and triglycerides), and inhibits the action of fat burning enzymes in your body.
Insulin also fuels hunger and sugar/carb cravings.
You may get away with eating lots of carbs while young, but the extra calories will start adding up once you hit your 30s, and your metabolism slows down.
If you have a family history of type 2 diabetes, you may also be more genetically prone to gain weight from carbs consumption.
3. Don't you need carbs for energy/survival?
Our ancestors survived as hunter-gatherers on less than 80 grams of carbohydrates per day (there was no agricultural know-how to farm crops back then), while still managing to hunt boars and escape predators.
As mentioned earlier, there's zero dietary requirement for carbs. Our body is perfectly capable of using other sources like fat and protein to make its own glucose (a process known as gluconeogenesis).
4. Wouldn't you just love to burn existing body fats as an energy source? Bad news for you, carb-lovers
The best part about using fat as energy, is losing the fat.
The problem is, if you're regularly consuming carb-rich foods, you've conditioned your body (and enzyme system) to primarily run on readily-available glucose. This prevents you from accessing stored body fat as an energy source, regardless of whether you are exercising or sedentary.
If you stick to a low carb diets for some time, your body switches over to fat-burning mode. This typically takes several weeks.
Minimizing my carbs intake where possible is one of the key reasons for my high metabolic rate. I can remain lean pretty much eating anything else I want to.
5. Sorry, but I need carbs to feel full/not cranky/not lethargic. Protein doesn't fill me up
You're not supposed to feel tired, weak or hungry on a low carb diet. If you do, it means you're not following it correctly.
There are many other factors that influence the "fullness" sensation, such as:
- Type and variety of food eaten
- Eating behaviour and environmental factors
- Portion size
- Availability of food choices
Furthermore, protein-rich foods have been shown to make you feel fuller than foods high in carbs. In this meta-analysis looking at the effects of increased protein intake on fullness, the lead author concluded that:
Higher protein intake led to a greater sensation of fullness.
I wasn't one of the study participants myself, but I can assure you that whenever I finish a whole chicken for dinner, I feel pretty damned stuffed after.
6. Ok I heard you - Eat less carbs, and then what?
Reducing "bad carbs" and exercising more is a good strategy for lowering insulin. As mentioned earlier, it's important to keep your blood insulin level low, because elevated insulin inhibits the fat burning process.
You should also increase your intake of protein, good fats, and fibre. Protein and good fats help you to feel full and satisfied, thereby making it easier for you to stick with a long-term healthy eating plan.
Good fats include:
- Fatty fish like salmon
- Olive oil
Supplement with plenty of fruits and vegetable for your fibre needs.
Some of my favourite sources of protein include:
- Chicken, steak
- Greek yoghurt (great as both a meat dip, and dessert)
For those of you who want to do a bit more reading into the scientific evidence for the benefits of a low-carb diet, here are some handily compiled papers by Harvard's School of Public Health.
PS If you still don't believe me that one can get by on no carbs, feel free to check back on whether I'm still alive 30 days later.
For any other sports/health-related questions, head over to Ask DxD to ask our team of doctors and dentists any questions for free!
Dr Ethan trained and practised in Edinburgh and London, before relocating to Singapore. He’s big on Sport Medicine and fitness. Other hobbies includes snowboarding, surfing, and a good cup of flat white.