5 Pitfalls of Restrictive Diets

a woman yawning with a laptop in front of her.Jun 2, 2023

By Caroline Young, MS, RD, LD, RYT

One in three U.S. consumers are following a specific diet on their quest for better health.

That’s according to the 2018 International Food Information Council (IFIC) Foundation survey of more than 1,000 Americans ages 18-80 [1]. The survey also showed people between ages 18 and 34 are more likely to diet, and the number of people dieting has more than doubled from the same survey last year.

The survey also highlighted participating consumers’ top nutrition behaviors and concerns, which include carb avoidance, fatigue and weight. As a registered dietitian nutritionist (RDN) I constantly hear from clients, friends and family members that they’re trying to avoid XYZ to lose weight and/or be healthy. That’s why I feel a responsibility to help well-intentioned consumers understand why extreme diets are not a solution to their health concerns.

Here are some reasons why following restrictive diets will hurt your health more than help it:

1) You’ll be fatigued.

The IFIC survey also revealed consumers are avoiding carbohydrates more than in the past. In fact, the most popular diets are typically low in carbs– often too low. The same survey revealed that 13 percent of consumers report energy to be a top health concern.

Carbs (found in bread, rice, pasta, fruit, etc.) are the most important source of energy for the brain and body and are critical in supporting a vibrant life. It is the macronutrient that the body wants to use first, before tapping into the others (fat and protein), which is why carbs should make up around half or more of our daily caloric intake [2][3].

Because of the essential role carbs play in our wellbeing, it makes sense then that as more people follow severely restrictive diets -- like the increasingly trendy “Keto” plan (the Ketogenic diet), which direct participants to consume dangerously low levels of carbs, the more they are finding themselves energy-deprived.

2) You’ll miss other key nutrients.

When food groups like carbs or fat are significantly reduced or eliminated, their nutrients go with them.

For instance, the Paleo Diet forbids legumes, which includes peanuts and peanut butter. Paleo diet followers miss out on the delicious and affordable plant-based protein peanuts deliver. Plus, they miss the good, or unsaturated, fats in peanuts. Eating more unsaturated fats than saturated fats (mainly in animal proteins) can lower the risk of heart disease and improve healthy (HDL) cholesterol levels [4]. Dietary fats are also necessary for the absorption of fat-soluble vitamins (A, D, E and K), which are essential for optimal health, including dental, skin and blood health [5].

Plus, the same IFIC survey showed that one-fifth of participants rate heart health as a top health concern and scientific research suggests (but doesn’t prove) that eating 1.5 ounces of peanuts per day as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. Click here to learn more about peanuts and heart health.

3) You’ll negatively affect your metabolism.

In the same IFIC survey that showed one in three people are dieting, 18 percent of consumers reported weight loss and management as a top health concern.

At first glance, it may seem puzzling that Americans’ weight continues to increase when more people simultaneously are going on diets like the Whole30, Paleo and Ketogenic [6].

But it actually makes sense. Sure, extreme diets and cleanses cause quick weight loss, but that weight is actually mostly water, muscle and bone. And weight loss from restricted eating is almost never maintained because the rigid food rules are nearly impossible to sustain long-term.

Chronic dieters also tend to have the issue of actually gaining additional weight, because they put their bodies in periods of restriction, and therefore lower the number of calories the body needs to stay alive, which is called our Basal Metabolic Rate (BMR). But once they go off the diet, they will gain the weight back (and sometimes more) because their BMR has changed, and their body grew accustomed to receiving a lower amount of energy (or calories) [7].

4) Your social life will suffer.

When you’re constantly worried about every morsel of food passing your lips and following food rules, you’re distracted from the most important aspects of life, such as relationships. Food is an integral part of every culture and most family traditions, and strict diets often keep people from engaging in social activities involving food. In a nutshell, the more food rules you have, the less you can go out and freely enjoy one of the pleasures of life – eating!

5) You’ll have a hard time focusing.

Often, food restriction and dieting can lead to a foggy mind and lack of focus. A balanced diet includes a variety of foods, which means it has foods from all food groups, including protein, grains, dairy, and fruits and vegetables. If the body and brain are not getting enough of a certain macronutrient group, such as carbs or fat, or enough energy (calories), they will not work optimally.[8]Plus, the body and brain are smart – if they’re not properly nourished, they will do what they can to push you to eat, like increasing your hunger signals and preoccupying your thoughts with food – which makes it nearly impossible to stay on task at work or be fully engaged with your loved ones.

On the contrary, when you eat a variety of nutrient-dense and pleasurable foods from all groups, you’ll enjoy consistent and sustained energy, a steady metabolism, and a clearer mind. Now, that sounds like health!

Consider working with a licensed registered dietitian in your area, who can work with you to develop a pleasurable and nutrient-dense eating pattern to fit your individual needs.

To read more about what makes up a truly balanced diet, click here.


[1] 2018 Food & Health Survey. International Food Information Council Foundation. https://www.foodinsight.org/2018-FHS-Report-FINAL.pdf. Published 2018. Accessed June 14, 2018.

[2] Carbohydrates. MedlinePlus.gov. https://medlineplus.gov/carbohydrates.html. Updated October 4, 2017. Accessed June 14, 2018.

[3] Dietary Reference Intakes: Macronutrients. The National Academies of Sciences Engineering Medicine. https://www.nal.usda.gov/sites/fnic.nal.usda.gov/files/uploads/macronutrients.pdf. Accessed June 14, 2018.

[4] More Key Topics. Choose MyPlate. https://www.myplate.gov/eat-healthy/more-key-topics. Accessed October 25, 2023.

[5] A Closer Look Inside Healthy Eating Patterns. Dietary Guidelines 2015-2020. https://health.gov/sites/default/files/2019-09/2015-2020_Dietary_Guidelines.pdf. Accessed October 25, 2023.

[6] Adult Obesity Facts. Center for Disease Control and Prevention. https://www.cdc.gov/obesity/data/adult.html. Updated May 17, 2022. Accessed October 25, 2023.

[7] Ellis, Esther. Staying Away from Fad Diets. https://www.eatright.org/health/wellness/diet-trends/staying-away-from-fad-diets. Published March 18, 2019. Accessed October 25, 2023.

[8] MyPlate. MyPlate. https://www.myplate.gov/. Updated April 19, 2017. Accessed June 14, 2018.

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