Low-carbohydrate diets have gained popularity despite ongoing debates about their nutritional value and long-term health effects. According to the 2020−2025 Dietary Guidelines Advisory Committee, there is insufficient evidence to support low-carbohydrate diets as a recommended eating pattern. However, some experts advocate for their inclusion in future dietary guidelines, particularly for individuals with certain cardiometabolic conditions. Others remain concerned about potential nutritional deficiencies and overall diet quality.
A recent study published in Frontiers in Nutrition assessed the calorie and nutrient content of three meticulously planned 7-day low-carb diets. The findings suggest that while these diets may provide sufficient nutrients, especially for middle-aged women, they do not fully meet the calorie and nutrient needs for all age and gender groups.
The study was funded by Simply Good Foods USA, Inc., known for its Atkins and Quest Nutrition brands. Notably, two of the study’s authors are employed by Simply Good Foods, and one is a shareholder. Despite this, Jonathan Clinthorne, PhD, a study author and Senior Director of Nutrition at Simply Good Foods, assured that the study used publicly available data and underwent peer review to ensure scientific integrity.
The low-carb meal plans analysed provided varying amounts of carbohydrates—20, 40, or 100 grams daily—along with differing levels of other nutrients. While the diets generally met or exceeded the daily calorie needs for women, none fully covered the calorie requirements for men. The diets, which replace carbohydrates with fats, resulted in higher fat and lower carbohydrate levels than typically recommended. Protein intake was above the recommended allowance but within acceptable ranges.
The meal plans provided adequate vitamins and calcium for certain age groups but fell short in other areas, such as iron for middle-aged women and calcium for older adults. Concerns include excessive sodium and saturated fat levels, although potassium was low, and the sodium-to-potassium ratio remained favourable. Fibre intake was inconsistent, with some groups failing to meet minimum recommendations.
The study’s findings highlight the potential benefits of low-carb diets, such as improved omega-6 to omega-3 fatty acid ratios, but also underscore the need for a balanced approach to ensure all nutritional needs are met. While low-carb diets can be beneficial, their practicality and long-term adherence present challenges.
