Are sweet potatoes fattening or good for weight loss?

Packed with nutrition and extremely versatile, sweet potatoes are a delicious root vegetable that should definitely have a place on your plate. You may only be accustomed to eating them during Thanks Giving and Christmas however after learning about all the health benefits that they bring, you will more than likely be persuaded to make them a regular part of your diet.

That being said, we need to address the question of whether sweet potatoes are a healthy choice when you are trying to lose weight. Can you eat them or will doing so lead to weight gain?

Nutritional Information

An average 5 inch long sweet potato contains:

Calories 112
Fat 0.1
Cholesterol 0
Sodium 72mg
Carbohydrates 26g
Fibre 3.9g
Sugar 5g
Protein 2g

Our healthy food finder tool will show you that sweet potatoes are the second most calorie dense vegetable, being beaten only by corn. However with that being said, for its size, it is still relatively low in calories. If you were on a 2000 calorie diet, eating a sweet potato would account for only around 5% of total calories.

How sweet potatoes can help with weight loss and weight management


Lets talk about some of the properties of sweet potatoes that make them a good food to add to a weight loss diet.

Low in calories

As mentioned above, sweet potatoes are fairly low in calories and this is a good thing if you are trying to control your weight.

A calorie is a unit of energy and different foods have different amounts of calories. For example, 100 g of macadamia nuts have 718 calories whereas 100 g of celery has only 16 calories! The large difference is because the macadamia nuts contain a lot of fat but the celery contains a lot of water.

When you are trying to lose weight, you need to eat fewer calories than what your body is using up. This calorie deficit causes your body to use its own fat reserves as a source of energy. If you are trying to gain weight, the opposite is true.

The number of calories you need to eat to lose, maintain or gain weight largely depends on your age, gender, height, current weight and activity levels. You can use our calorie estimator tool (below) to determine this number.

Gender Age Weight Switch to lbs Height Switch to feet and inches Activity Level

This calculator will never show a number below 1000 calories per day. Please speak to a qualified health professional before attempting to eat less than that.

For example, a 40 year old woman who weighs 75 kg, is 150 cm tall and exercises 4 times a week will need to eat around 1645 calories a day to begin losing weight. If she starts to eat more than 2100 calories a day, she will most likely gain weight.

On a 1645 calorie diet, she could safely include one sweet potato, which would account for roughly 7% of total daily calories. As long as she prepares the sweet potato in a healthy way, it won’t negatively affect her total calorie consumption.

Dietary Fiber

Sweet potatoes contain a decent amount of fiber, with an average sweet potato providing almost 4 g. A lot of the fiber is found in the skin of the sweet potato, so it’s a good idea to not throw this part away.

Fiber has been shown to help with weight loss mainly due to the reason that it absorbs water and helps to keep you filling fuller for longer.

For example, this study wanted to see what effect increasing fiber intake had on weight. 240 adults with metabolic syndrome took part and they were randomly assigned to one of two diets:

  • The American Heart Association (AHA) diet which required the participants to eat more vegetables, fruits, high fiber foods, lean protein & fish and cut back on sugar, fat, salt & alcohol.
  • A diet that simply required participants to eat 30 g of fiber, or more.

Neither group received any additional information such as a specific exercise plan to follow. The study found that even though the participants on the AHA diet lost slightly more weight on average, making a simple change and adding fiber to the diet resulted in weight loss.

There are two main types of fiber, soluble and insoluble fiber. Soluble fiber forms a gel when mixed with water and keeps you feeling fuller for longer. A sweet potato contains approximately 1.8 g of soluble fiber. Insoluble fiber adds bulk to your stool, which makes going to the bathroom a pleasant experience. Sweet potato contains around 2.2 g of this type of fiber.

Scientific studies

There haven’t been many studies to determine how adding sweet potato to the diet affects weight in humans, however a few studies have been carried out on rats.

This study tested to see what effect consuming sweet potato extract had on appetite. The results showed that rats who consumed the extract ended up eating less food throughout the day, compared to those who didn’t. This is thought to be because the sweet potato extract increased satiety (fullness). This is important for weight management as being able to control how much you eat plays a crucial part.

Another study showed that extracts from purple sweet potatoes were able to suppress the growth of fat droplets.

One thing to keep in mind is that these studies were carried out by using sweet potato extract and they also did not analyse what effect directly eating sweet potato had on humans. That being said, the studies did provide promising results.

What about the carbohydrate content in sweet potatoes?

It is true that low carb diets are beneficial for weight loss. People who are trying to lose weight tend to be scared of carbohydrates and try to avoid them as much as possible. However, there are good carbohydrates and bad ones and sweet potato is considered to be a good carb.

The glycemic index (GI) monitors the effect that a certain food will have on your blood sugar levels, both in terms of the speed and amount it raises your blood glucose. The index uses glucose as a reference point to compare all other foods to – pure glucose has a GI of 100. Sweet potatoes rank between 44 and 94 depending on how they are prepared, but on average they have a GI of 70, which is considered to be high.

However, a more accurate factor to take into consideration is the glycemic load (GL). This is calculated by taking the glycemic index of a food and multiplying it by the amount of carbohydrate found in 1 gram of that food. The GL of sweet potato is 22.

Sweet potatoes are also a source of complex carbs. Unlike simple carbs that are obtained from processed foods, complex carbs are digested at a steady pace. This means that they also release energy at a good pace and don’t cause an overly rapid spike in blood glucose levels, like eating candy would.

Your body needs carbohydrates in order to remain healthy. For more information, read our in depth guide on weight loss diets here.

How to prepare sweet potato in a healthy way

Any healthy food can be made unhealthy if it is cooked incorrectly.

For example, deep frying sweet potato will lead to a huge increase in calories, saturated fat and cholesterol. Boiling, grilling and baking are better options.

The great thing about sweet potato is that it can be prepared in many different ways.

Use it in smoothies

Who would have ever thought you can use sweet potato in a smoothie? Well you can! Our sweet beta carotene smoothie recipe is super delicious and bursting with vitamin A!

Make sweet potato mash

You are probably used to making potato mash using regular old white potatoes but did you know that you can use sweet potatoes as well? The recipe below is super quick and easy to make.

Oven baked sweet potato wedges

Another great recipe from Michael at Lean Body Lifestyle are these oven baked sweet potato wedges. This is a much healthier option than deep fried potato wedges, which may taste great but aren’t doing your waist line any favours.

When eating your sweet potatoes, stay away from unhealthy calorie and sugar loaded toppings such as mayonnaise and cream cheese. Non fat Greek yogurt and cottage cheese are rich in protein and much healthier options.

Other health benefits of sweet potatoes

Sweet potatoes are full of vitamins, minerals and antioxidants, which bring many health benefits with them. Even if you are not trying to lose weight, you should definitely add them to your diet:

They are an excellent source of vitamin A

The orange colour of sweet potatoes tells you that they are rich in beta-carotene, an antioxidant that is converted into vitamin A. One medium baked sweet potato provides more than 400% of your daily recommended amount of vitamin A.

Vitamin A helps your vision, maintains healthy skin and has even been associated with reducing the risk of developing certain types of cancer.

They are rich in vitamin C

Sweet potatoes are also rich in vitamin C, with one baked potato providing you with 37% of your daily requirement.

Vitamin C keep your immune system in tip top shape, helps with bone formation and increases collage production, which in turn promotes healthy skin.

They are full of antioxidants

Your body is always fighting free radical that cause oxidation and damage to cells. If too much damage is done, serious diseases such as cancer can result.

Blueberries have been long known to be an excellent source of antioxidants, however purple sweet potatoes were shown to have 3 times more antioxidant activity!


There is no doubt that sweet potatoes are a great food to add to your diet. They are also a good choice when you are trying to manage your weight.

At the end of the day, it comes down to calories. If you can manage your calorie consumption and expenditure correctly by eating nutritious food and exercising regularly, you will definitely be able to control your weight!

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