As a personal trainer in London, you’d not be surprised to hear that I’m asked about carbs all the time. How many carbs should I eat a day? Are carbs bad for you? Are carbs good for you? Are carbs the best source of energy, or fat? Should I follow a low-carb diet? Which carbs are good for you? What are complex carbohydrates? Is it bad to eat carbs last thing at night? The list is endless.
The role of carbohydrates
The role of carbohydrates is to provide energy for the body and brain. Low carb advocates condemn carbs on the basis that they “only provide energy”, which is a pretty crazy criticism. Energy from food is pretty important, and carbohydrates are the body and brain’s preferred energy source.
Your body can also burn fat as fuel, and fat is used as energy alongside carbohydrates in different amounts and proportions depending on a whole range of variables. But carbohydrates are a very important energy source, so don’t listen to the zero carb brigade. One of the leading enemies of carbs in today’s nutrition world is Zoe Harcombe. Her book The Obesity Epidemic is full of carb-condemnation. Although she rightly condemns processed/refined/junk carbs, she tars all carbs with the same brush. Worst of all, she makes the false assertion that you can’t burn body fat if you have any carbohydrates in your body.
Carbohydrates not only provide energy, but unprocessed carbohydrate-based foods also provide (in varying amounts depending on the food in question) vitamins, minerals, and fibre, all of which are vital for our health.
How many carbs should you eat?
There is no “one size fits all” answer to this question, but there are several statements which hold true for everyone. It is possible to eat too few carbs, and an increasing number of people are doing this. The result, you end up eating too few calories, or too high a proportion of fat and/or protein, all of which have negative effects on your health. Excessive restriction of carbs also means you get too little fibre, which increases risk of high cholesterol and certain cancers.
It is also possible to eat too many carbs, and many people fall into this trap too. Excess carbs are converted to body fat, once your glycogen stores are full. (Carbs are converted to glucose when digested and absorbed into the bloodstream, and glucose not used immediately for energy is stored in the liver and muscles as glycogen.)
And it is also possible to eat the wrong kind of carbs. These are the processed carbs, refined carbs, ie- manufactured junk food and drinks. These lead to spikes in blood sugar, wreck your insulin system, and can lead to a range of diseases like diabetes. It’s also possible to eat too much fruit, and excess fruit sugar (fructose) is converted to fat in the liver. Stick to ‘slow-release’ carbs which result in more stable blood-sugar levels, and less stress on your insulin system.
Your carbohydrate requirement varies according to your age, gender, activity levels (and type of activity), and whether you need to lose weight or gain weight. You also need to take into account your unique metabolism, hormonal levels, energy levels (both physical and mental), medical conditions and so on.
An established general rule is to consume around 40-50% of your daily calorie needs from carbs. So for a woman who needs around 2,000 calories a day, around 1,000 calories should come from carbs (good carbs though! see below), which equates to around 250g carbs. Remember that a gram of carbs is 4 calories (a gram of protein is also 4 calories, and a gram of fat is 9 calories). So if you have 5 meals/snacks a day, this is around 50g carbs per meal.
However, I think a better proportion is around 40% of your total calories from carbs, and 30% from protein, and 30% from fat. People have gone too far in the direction of ‘low fat’ to the detriment of their health. Again, there are good fats and bad fats, and fats in between, so it’s not just a question of how much you should eat, but exactly what foods you should eat or not eat.
How many carbs per pound of body-weight should you eat?
A good general rule is 1.5 – 2 grams of carbs per pound of body-weight, but you need to take into account the other factors mentioned above to determine what’s right for you. So a 180 lb male should aim to eat around 360g carbs a day at most, and at least 270g carbs.
If you’re looking to bulk up and gain weight, particularly if you’re bodybuilding or training intensively, your carbohydrate requirement will be higher, around 3 – 4 grams of carbs per pound of body-weight. But make sure you only eat these higher levels of carbs on days you’re training intensively, and bring the carb intake down on rest days.
And never sacrifice the quality of carbs when you’re bulking up. “Eat clean” as bodybuilders say, which means no junk, no refined sugars.
Good carbs v bad carbs
Here’s a list of ‘good carbs’ you should stick to:
Oats (either hot as porridge, or just cold in natural yoghurt or cold milk, but never oats with added sugar)
Vegetables (particularly green leafy veg. Although not usually classed as carbs, vegetables are a combination of carbohydrates and fibre, with a high concentration of vitamins and minerals, so eat plenty of veg)
Fruit (eat in very small quantities, and mainly oranges for the vitamin C, no more than 2-3 fruit a day)
Unprocessed Grains (stick to unprocessed grains like brown rice, bulgar wheat, quinoa, millet)
Wholemeal brown bread (eat in small amounts, see my blog about bread)
Beans & pulses (lentils, kidney beans, chickpeas)
Sweet potatoes, yams, baked potatoes
And avoid these ‘bad carbs’:
All refined grains/pasta (white rice, white bread, white noodles, white pasta, pizza bases made with processed white flour, boxes of breakfast cereals, even the so-called ‘healthy’ ones)
All junk confectionery, cakes, biscuits, pastries, and all the Mexican foods like nachos, tacos, tortillas, burritos (unless they’re wholewheat, in which case eat in moderation)
All sugary and fizzy drinks, all fruit juice, anything that contains high fructose corn syrup
Should I avoid carbs in the evening?
Most people believe that you should avoid carbs last thing at night. I’ll explore this issue in a future blog post. The whole issue of carb timing is a big subject in itself.
Please leave your comments in the comments section below. If you want anything in this article explained in more detail, ask in the comments section and I’ll reply below.