Do Carbs Make You Fat?

by Ahmed Zayed, MD on December 4, 2019
Last updated on May 23, 2021

Perhaps, portion control and exercise are both excellent means to manage your weight. Do you know that even if two different meals have the same calorie count may lead to either weight gain or weight loss? The key for you to lose weight is actually the number of carbohydrates in your meal. Too many carbs in your daily meal can actually lead to weight gain (1)

pesto pasta on a plate

What are Carbs?

One of the main building blocks composing all foods you eat, together with fat and protein, is carbohydrates. It is a macronutrient which is very crucial to for your body to function properly. Usually, carbs are divided into three groups- sugar, starch, and dietary fiber.


Sugars or simple carbohydrates include glucose, fructose, and lactose. These can be taken from nutritious whole fruits like apples. They tend to be palatable and sweet (2). These are considered as simple short-chain compounds either as monosaccharides or as disaccharides. 


Starches or complex carbohydrates are usually taken from rice, bread, vegetables, whole grains, and cereals. These are considered as longer chain compounds or as polysaccharides. Starches are usually produced by green plants to serve as energy storage. 

Dietary fiber

Just like starches, dietary fibers are also considered as polysaccharides. But the difference is that it cannot be digested by the gut, though it has a crucial role in your diet such as reducing your risk of various health problems such as diabetes and heart disease (3)

Since carbs are macronutrients, they provide calories and energy your body needs. According to the American Diabetes Association, the main source of energy needed by your body is carbs (4). Carbs in short of carbohydrates and from the name itself contain carbon, hydrogen, and oxygen.  

Macronutrients are very important for your body to function properly; that is why you need them in large amounts. These macronutrients are taken from your diet, although your body also produces such on its own. 

According to the National Institutes of Health, adults recommended daily amount of carbohydrates is 135 grams. Aside from that, it is suggested that each of us should have our own carb goals. Usually, your carbs should be from 45 to 65 percent of your total calorie intake. 

Since four calories are equal to 1 gram of carbs, you need to limit your diet with 1,800 calories a day in order to have 202 grams or 292 grams of carbs in the low or high end respectively. But, if you have diabetes, you should not exceed more than 200 grams of carbs a day. And if you are pregnant, your body needs at least 175 grams of carbs every day (5)

Benefits of Carbs

Mental health

Carbs are vital for our body. They serve as fuel for our central nervous system. It means that they have a huge role in our brain function. They influence our memory, mood, and a lot more. They also allow fat metabolism. In fact, our daily needed carbs are based on the amount needed by our brain to function properly. 

A study has shown that a person who has a low-carb, high-fat diet will most likely experience depression, anxiety, and anger. It was suspected that carbs help in the production of serotonin in the brain. 

You will most likely experience depression if you have low levels of serotonin. Serotonin is a vital neurotransmitter and chemical in your body, which can help in regulating your appetite, mood, social behavior, sleep, digestion, memory, and sexual desire (6).

Weight loss

The right amount and kind of carbs can actually aid you to maintain and lose weight. Usually, carbs such as vegetables and whole grains contain fiber. Oftentimes, it is hard to have the right amount of fiber if you have a low-carb diet. Remember that dietary fiber can help you become satiated.

A study among middle-aged women has shown that those who consume more fiber experience more weight loss, while those who consume less fiber experience weight gain (7). Another study has shown that a low-fat diet, not a low-carb diet is responsible for weight loss (8)

Another study has shown that both a low-fat diet and a low-carb diet are capable of helping you lose weight, though a low-carb diet is the fastest way. In the long term, both diets have the same success rates. 

Good nutrient source

Whole grains are one of the most well-known sources of good carbs. People who eat the right amount of whole grains obtain higher amounts of energy, fiber, micronutrients, and polyunsaturated fats. Foods such as sweet potatoes, leafy greens, citruses, berries, and apples contain nutrients. 

Heart health

Dietary fiber aids in lowering cholesterol. Your digestive system actually requires bile acids. A part of these bile acids is made with cholesterol. In order to make more bile acids, the cholesterol is pulled by your liver from the blood as your digestion is improved. This process helps in reducing the amount of bad cholesterol in your body. 

Reasons Why We Gain Weight

We all know that obesity is prevalent all throughout the world. In fact, it is linked with various conditions including elevated blood sugar, high blood pressure, and poor blood lipid profile. People with a condition related to obesity, collectively known as metabolic syndrome, are at more risk of type 2 diabetes and heart disease, compared to those with normal weight. (8)

Here are the five common factors why we gain weight:


Do you know that genes have a lot to do with obesity? It was found out those children whose parents are obese have a high risk of becoming obese too. Although obesity does not mean that it is predetermined, genes have a key effect on whether or not children will become obese. Well, this has something to do with the signals they conveyed to their genes as well as the environment.

Engineered junk foods

Junk foods are usually offered to have a longer shelf life, as well as cheap cost and great taste. Manufacturers tend to make junk foods become tasty not only to increase sales but also to promote overeating. And you know what happens when you overeat. 

Food addiction

Usually, the reward centers in your brain are stimulated when you eat a lot of high-fat, sugar-sweetened junk foods (9). In fact, these foods are equated to abused drugs like cocaine, cannabis, nicotine, and alcohol. 

Individuals who are susceptible usually get addicted to junk foods. If you are addicted to junk foods, you tend to be out of control when it comes to your eating behavior. And this kind of behavior is compared to those who are struggling with addiction to drugs and alcohol. 


Insulin helps in regulating the energy you store in your body. One of the key functions of insulin is to signal your cells to store fats and to maintain those fats they already keep. Some diets promote insulin resistance, especially in obese individuals. This allows the insulin levels to increase, which results in the storing of the energy in the fat cells, instead of using it for your daily activities (10)


As always mentioned, not all sugar is bad for your health. If you consume sugar in excess, the biochemistry and the hormones of your body change. This, in turn, promotes weight gain. Most of the fructose you get is from added sugar, while most of the glucose you get is from various foods, including starches. Indeed, sugar can give you energy, but it can ultimately lead to obesity. 

Do Carbs Contribute to Weight Gain?

Any food can actually make you fat if you consume them in excess amounts. Whether your diet is high in carbs or high in fats, you will most likely gain weight if the energy you consume is much higher compared to your energy expenditure (11).

Since carbs are divided into three groups, let us discuss why each of these can actually make you fat:

Consuming too much sugar

One of the leading causes of various diseases for decades is obesity. Usually, people tend to point sugar as the main culprit of obesity. It was shown that about 12.1 percent of the total calorie intake of adults comes from sugar. 

Not all sugar is bad for your health. In fact, the right amount and kind of sugar are very useful for your diet as it contains minerals, vitamins, and other nutrients. On the other hand, foods that are high in sugar are also high in calories. It means that this can widely contribute to your weight gain.

When you eat foods rich in sugar, the sugar is then broken down into glucose. Glucose is then carried into the different organs and tissues of your body through your blood and uses this for energy. If your body does not need energy, this is stored as glycogen in your muscles and liver. Once it is already full, glucose is converted to fats (12)

Indeed, a lot of healthy foods are great sources of sugar. But, the reason why it makes us obese is that it is easy for us to take a huge amount of sugar without realizing it. Sugar is mostly used as an additive for the purpose of increasing palatability and sweetness in various products, especially in confectionery, fast food, and convenience meals. 

Consuming too much starch

Your body produces insulin in order to remove glucose from your bloodstream if you eat a starchy carb. If the glucose is not burned, then it is stored as fats. Aside from that, your body stores extra calories in case you won’t be able to gather or hunt calories. 

Your body converts the extra starch into fats in the form of triglycerides. But, if you change your diet, by consuming less starch and more fats, your triglyceride level will quickly drop into range. 

Eating too many carbs can actually increase your blood glucose levels. In order to get rid of the extra sugar, your body is prompted to produce insulin. It then results in a decrease in your blood sugar level, which makes you become fatigued. Your brain is also incited to signal to eat even if you just consumed food (13)

Lack of fiber

Whole-grain foods are great sources of fiber. Foods with high fiber can actually help you become full. If you are full, you will be less likely to consume more. In fact, if your diet lacks fiber, you will most likely gain fat. The reason for this is that fiber is very crucial in controlling your appetite. Consuming fiber can actually make you become fuller for longer hours. 

A study has shown that consuming excess fiber of about 14 grams a day can actually help you reduce your calorie intake for up to 10 percent (14). If this is the case, then you can lose up to 1.9 kg in just four months, and that is by merely taking fiber. 

The mere fact that fiber can make you feel full helps you maintain your waistline. Eating vegetables, such as legumes and beans, can actually increase your fiber intake. But if you find it hard to eat vegetables, then you have the option of taking soluble fiber supplements. 


Carbs are very crucial to our entire well-being as it is a macronutrient required by our body for growth and development. Not all carbs can make us fat, but too much of it can eventually lead to weight gain. That is the reason why if we want to lose weight, we should choose to consume the right kind of diet as well as to engage in physical activities regularly. 


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