Low Carb

Can I Lose Weight on 100 Grams of Carbs a Day?

Max Carmody, MSc

It is possible to lose weight on 100 carbs a day, I personally have lost weight on roughly 100 carbs a day. Multiple diets, including the Atkins 100 diet, are based around the principle of consuming 100 carbs daily.

What are Carbs?

Carbohydrates, or carbs for short, are one of the macronutrients that our body needs in large amounts to survive. The other ones are protein, and fat. These are in contrast to micronutrients, vitamins and minerals, that we need only in small amounts. Carbs are sugars, starches, and fiber. Your body turns carbs into glucose, to give you the energy to function. The digestive system breaks down carbs into blood sugar, or glucose. Carbs are in things like milk, grain, and fruits. There are different types of carbs, the two main types are simple, and complex. Simple carbs tend to provide you with short bursts of energy. Complex carbs are a longer lasting energy source that take longer for your body to break down. Simple carbs tend to be things like table sugar, fruit and milk. Complex carbs tend to be found in things like whole grains.

Low Carb Diet

On a low carb diet, the goal is to, as the name suggests, reduce your daily carb intake. Typically, anything under about 130 grams of carbs is considered to be low carb. So eating 100 grams a day would fall under the moderate low carb diet category. To find out more about if 100 grams of carbs a day is low carb, you can read an article here that I wrote on the subject. Some low carb diets, especially the Keto diet, involve eating even fewer carbs, as few as 20 to 50 grams per day. When you reduce your daily carb intake, you need to make it up with the other macronutrients. This can be either fat, protein, or both. There is not one single type of low carb diets, however, there are many different types.

Evidence for Low Carb

There has been tons of evidence showing that low carb diets do indeed, lead to weight loss. And 100 grams of carbs is generally considered to be low carb. Over 20 studies have compared low fat to low carb diets. They tend to perform especially well for the first 6 months, with fewer notable differences after the 6 month mark. In one study, participants followed either a low carb, or a low fat, calorie restricted diet for 12 months. After 6 months, the low carb group had lost 7% of body weight, compared to 3% for the low fat group. In another 6 month study following people with severe obesity, after 6 months the low fat group had lost an average of 12.8 pounds, and the low carb group had lost an average of 4.2 pounds. Low carb diets are not the only type of diet that work, and there are plenty of others as well that will work. However, low carb diets seem to be at least as effective as many of them, and possibly more, especially for the first 6 months.

Atkins 100

There is an entire commercial diet focused around eating 100 grams of carbs per day. This is the Atkins 100 diet. I have never followed it myself EXACTLY, but I have followed other diets very similar to it, so I believe that it works. Also, I don’t think that an entire very successful commercial diet would be based around the 100 grams of carbs mark, if it didn’t work. On an Atkins diet, you consume 100 grams of net carbs per day. Net carbs are the total carbs that your body actually uses for energy, subtracting fiber. So the Atkins 100 plan is not too restrictive. No food groups are completely off limits. You are encouraged to get 85 grams of carbs a day from things like grains. If you are interested in learning generally what a good carb range is, here is an article I wrote about that.

My Experience

Generally when I am on a low carb diet, I eat under 100 grams of carbs a day. However, for a little while, I went on a diet where I ate roughly 100 grams of carbs a day, possibly even slightly more, and I lost almost 6 pounds in 5 days. Here is the exact book that I followed, if you want to check it out. To be fair, this was for the first week of the diet, so some of it was probably water weight.

I’ll give you examples of how I was eating. For breakfast every morning I was having special K (without added sugar or toppings) and berries. A cup of special K has about 23 grams of carbs, and I may have been having more than a cup of it. For lunch I was having very few carbs, spinach with a low carb dressing, and grilled chicken. For dinner I was eating a steak (I like them very rare, although that’s irrelevant to the carb intake)  with green beans or a frozen vegetable, and a cup of Basmati rice. One cup of Basmati rice contains about 44 grams of carbs. The book actually recommended a cup and a half of Basmati rice, but I felt that was more than I needed.


I felt that this diet worked pretty well. I was also exercising regularly on it. And I was drinking some wine in the evenings, mostly Rose. But I was definitely losing weight on it, without feeling that it was too restrictive. Many sources, including healthline.com, state that it is possible to lost weight on 100 carbs a day, but you also need to be careful about portion size and that sort of thing.

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