Carbs often get a bad rap. They’re singled out as the culprit of weight gain, and several fad diets cut it out almost entirely.

But not all carbs are bad for you. Some contain many health benefits that make them essential to any healthy diet. Your body needs carbs in order to function properly. That said, not all carbs are made equal — some are better for your body than others. Picking the right carbs is key to better health and weight loss.

So before you go cutting out carbs from your diet in an effort to lose weight, here’s what you need to know.

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Most carbohydrates can be found naturally in plant-based foods, such as grains. Processed foods also contain some form of carbs such as starch or added sugar, but the most common sources of carbs include fruits, vegetables, nuts, grains, seeds, milk and legumes. The three main types of carbohydrates include:

Sugar: the simplest form of carbs found naturally in fruits and vegetables, milk and milk products. You may find it in the form of fructose (fruit sugar), sucrose (table sugar) or lactose (milk sugar) in ingredients lists.

Starch: a complex carb comprised of multiple sugar units bonded together. It is found naturally in grains, vegetables and beans.

Fibre: another complex carb that occurs naturally in fruits, vegetables, whole grains, and beans.

Carbs contain B vitamins, iron, calcium, and fibre, all of which are necessary for regular bodily function, right down to the cellular level (vitamin B12, in particular, helps to keep the body’s nerve and blood cells in tip-top condition). They also influence the central nervous system and fuel our working muscles.

They get converted into glucose in our bloodstream, providing us with energy that we expend even just by sitting still.

PSA: Carbs don’t make you fat. Your sedentary lifestyle does. Too much input and not enough output is what causes us to pack on the pounds. When we take in more than we expend through daily activity, the unused carbs get converted into fatty acids and stored in the body as fat.

In fact, carbs enable fat metabolism by preventing the body from using protein as an energy source, thereby allowing the amino acids in protein to build fat-burning muscles. The National Institutes of Health recommends that carbs should make up 45 per cent to 65 per cent of total daily calorie intake.

The term “good carbs” refers to whole foods that contain vitamins and minerals, fibre, as well as protective plant compounds. These carbs are digested more slowly, and this slower conversion into glucose means that your insulin levels don’t see very drastic fluctuations and your body has a steadier stream of energy.

The protective compounds and steady sugar level are what make “good carbs” good.

“Bad carbs”, on the other hand, contain an excessive amount of sugar. Refined grains such as white rice, white bread, pastries, sugar, pasta and more are deemed “bad” because they don’t have much — or any — nutrients at all. Plus, they get converted into glucose very quickly, leading to unhealthy fluctuations in blood-sugar levels, which can result in Type 2 diabetes over time.

Carbs support brain function and influence our mood and memory. Not only do they boost cognition, they also provide the blood-glucose your brain needs to perform normally. And the brain uses up 60 per cent of the blood-glucose in your body. Hypoglycemia is an extreme case when the concentration of blood-glucose falls, and the brain is literally starved for fuel, causing lightheadedness, confusion, slurred speech and even death. So skimp on carbs, and you’ll find yourself turning sluggish, unfocused, prone to forgetting things and becoming moody.

(Also read: 5 Warning Signs You’re Not Eating Enough Carbs)

Studies have shown that a high-carb diet may protect us from age-related illnesses such as cardiovascular disease, cancer, and Alzheimer’s. People who live in the world’s Blue Zones (places such as Okinawa and Sardinia) tend to have a longer-than-average life expectancy, and that’s largely attributed to their diet and way of life.

In Okinawa and Sardinia, for instance, their traditional diet is carb-heavy, focusing on grains and starchy vegetables — quite the opposite of the high-protein, low-carb formula that popular diets advocate. In fact, the Okinawan Ratio of carbs to protein is 10:1. The low-GI, high-fibre carb that makes up most of their diet is the Okinawan sweet potato. In short, it’s the type of carbs you eat that matters.

Eating carbs, especially before working out, reduces your chances of catching a bug or falling sick, because it boosts your cytokine levels. Cytokines are molecules that regulate our immune system, protecting our body against the stress induced by physical activity and exertion. So have some slow-burning carbs like a bowl of oats a couple of hours before you hit the gym.

Some claim that eating carbs later in the day causes the body to store more fat, but there’s no scientific proof of that. There is no ideal time to eat carbs, although eating it during the day means you have more hours to expend it. Still, your body burns fuel even when you’re sleeping, so the carbs you eat at dinner are meant to tide you through the night till breakfast the next morning.

(Also read: Here’s Why A Low-Carb Diet Could Be A Really Bad Idea)

Even a stalk of celery contains 2g of carbs, and a 200ml glass of milk contains 10g of carbs. Most foods contain at least a trace amount of carbs, and while you might think you’re saving your waistline by sticking to only ‘zero carb’ food, you’re probably depriving your body of the energy and nutrients it needs. Even low-carb diets such as Atkins or Keto would still involve fruits and vegetables, and perhaps small amounts of healthy starches such as oats.

(Also read: 7 Ways A Low-Carb Diet is Bad For You)

As mentioned, sugar is a refined carb, and too much of which can spike your insulin levels and lead to Type 2 diabetes. Studies have shown that people who consume high-GI carbs (i.e. carbs that cause huge fluctuations in blood-sugar level) experience activation in the brain region similar to that of drug addicts and problem gamblers.

(Also read: 9 Scary Things Sugar Does to Your Body)

So how do you tame that sweet tooth? Indulge it at breakfast — have that fruit smoothie or a small pastry so that you will crave it less later in the day (and end up reaching for a giant bagel or packet of chips).

And if you think sweeteners are the solution, think again. Artificial sugars can impair the brain’s ability to gauge the sweetness in your food or drink and the actual amount of calories in your food or drink — so even if you avoid carbs, you’re still craving that sugar hit. Better to ditch the Diet Coke and reach for freshly-squeezed fruit juice instead.