Low-carb diets have exploded in popularity over the past decade, praised for their effectiveness in managing Type 2 diabetes and obesity but critics have long argued that cutting carbs means missing out on essential nutrients. Now, a groundbreaking study is flipping that narrative, showing that well-planned low-carb diets can be both nutritionally complete and sustainable.

Breaking down the study

Published in Frontiers in Nutrition, the study was led by researchers from Simply Good Foods USA, Inc. and the University of Vermont. They designed three different 7-day meal plans, each representing a different level of carbohydrate restriction:

1. VLCD20 (Very Low-Carb Diet, 20 grams of net carbs per day) – Designed for those aiming to enter ketosis, a metabolic state where the body burns fat instead of carbohydrates.
2. VLCD40 (Moderate Low-Carb Diet, 40 grams per day) – Provides more flexibility while maintaining many ketogenic benefits.
3. LCD100 (Liberal Low-Carb Diet, 100 grams per day) – A more sustainable approach that fits into everyday life.

For context, the average American is recommended to consume 130 grams of carbohydrates daily. The study analysed how well these plans met essential nutrient needs, and the results were surprising.

Debunking the nutrient deficiency myth

A common criticism of low-carb diets is that they may lack important vitamins and minerals. However, this new study found that all three low-carb plans exceeded recommendations for essential nutrients, including vitamins A, C, D, E, K, and B-complex, as well as key minerals like calcium, zinc and magnesium.

According to co-author Dr Beth Bradley from the University of Vermont, “Our findings suggest that, beyond their well-known role in weight management, low-carb eating patterns can actually improve diet quality and help close nutrient gaps.”

Fibre and low-carb? Yes, it’s possible!

Another misconception is that reducing carbs means sacrificing fibre, which is essential for digestion and gut health, but the study revealed that fibre intake remained strong, particularly in the moderate and liberal low-carb plans. Dr Bradley clarified, “The idea that a low-carb diet must also be low in fibre isn’t supported by the data. Fibre-rich foods like non-starchy vegetables, nuts, seeds and even certain fruits can be included while still keeping net carbs in check.”

The role of fats in a low-carb diet

Since low-carb diets replace carbohydrates with fats, concerns about fat intake are common; however, the study found that these meal plans promoted a healthier fat balance than the typical American diet. The omega-6 to omega-3 fat ratio improved dramatically, shifting from the usual 8:1 ratio to a much healthier 1.5:1 to 2.6:1.

While the plans contained more saturated fat than traditional dietary guidelines recommend, researchers noted that the source of the fat matters. Saturated fat from whole foods like dairy and coconut oil appears to impact health differently than processed sources.

Protein: More than enough for muscle and metabolism

All three meal plans exceeded the minimum protein recommendations, falling within the acceptable 10-35% of daily calorie intake.

• Higher protein intake helps preserve muscle mass during weight loss.
• It also supports healthy ageing, which is particularly important for middle-aged and older adults.

Sodium vs potassium: A better balance for heart health

Sodium intake in these plans slightly exceeded guidelines, but the sodium-to-potassium ratio—a key indicator of heart health—was far better than the average American diet. The research suggested that this balance may be more important than sodium intake alone when it comes to cardiovascular health.

Who benefits most from a low-carb diet?

The study found that low-carb diets met or exceeded the nutritional needs of most adults, particularly middle-aged women, who make up a large percentage of low-carb dieters. However, it highlighted a few areas where extra attention may be needed:

• Younger women may require additional iron.
• Older adults might need extra calcium to meet their higher bone health requirements.

This research challenged the long-held belief that low-carb diets are nutritionally deficient where, in reality, they can provide complete nutrition while helping manage conditions like Type 2 diabetes and obesity. The key is thoughtful meal planning, focusing on whole, nutrient-dense foods rather than simply cutting carbs.

Dr Bradley summed it up, “Nutrition is more than just numbers on a food label. The quality of the foods you eat and how they fit into your overall diet plays a bigger role in your health than total carb count alone.”

If you are considering a low-carb lifestyle, here’s what to remember:

• Choose whole, nutrient-dense foods over highly processed options.
• Incorporate fibre-rich veggies, nuts, and seeds to maintain gut health.
• Balance healthy fats to support heart and brain health.
• Prioritise protein to preserve muscle and stay satiated.
• Be mindful of key nutrients like iron and calcium, depending on your age and gender.

While low-carb diets are not for everyone, this study proved they can be a nutritionally complete and sustainable option for those who plan wisely. With the right approach, you can fuel your body effectively without missing out on essential nutrients.

Disclaimer: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.