It’s not just about the number of carbs
The researchers from the Harvard T.H. Chan School of Public Health analysed the diets and weights of over 123,000 healthy adults. Participant provided self-reports of their diets and weights every 4 years since the start of the data collection in 1986. The diets were scored based on how well they matched 5 different categories of a low-carbohydrate diet:
- Total low-carbohydrate diet (TLCD), emphasising overall lower carbohydrate intake
- Animal-based low-carbohydrate diet (ALCD), emphasising animal-based proteins and fats
- Vegetable-based low-carbohydrate diet (VLCD), emphasizing plant-based proteins and fats
- Healthy low-carbohydrate diet (HLCD), emphasising plant-based proteins and healthy fats, and lower intake of refined carbohydrates
- Unhealthy low-carbohydrate diet (ULCD), emphasising animal-based proteins, unhealthy fats, and refined carbohydrates
“Our study goes beyond the simple question of, ‘To carb or not to carb?’ It dissects the low-carbohydrate diet and provides a nuanced look at how the composition of these diets can affect health over years, not just weeks or months,” said lead author Binkai Liu.
Healthy low carb was the best for weight management
The study found that participants who increased their adherence to TLCD, ALCD, and ULCD on average gained more weight compared to those who increased their adherence to HLCD over time. The HLCD was the best for long-term weight management especially for overweight or obese people and those younger than 55 years old. The VLCD showed mixed results.
“The key takeaway here is that not all low-carbohydrate diets are created equal when it comes to managing weight in the long term. Our findings suggest that public health initiatives should continue to promote dietary patterns that emphasise healthful foods like whole grains, fruits, vegetables, and low-fat dairy products,” said senior author Qi Sun.
What changes should you make?
The healthy low-carbohydrate diet is all about choosing healthful types of carbs and fats and plant protein. Here is how the study differentiates between healthy and unhealthy carbs:
- Less healthful carbohydrates include those from potatoes, added sugar, and refined grains
- Healthful carbohydrates include those from non-starchy vegetables (excluding potatoes and French fries), fruits (excluding fruit juice), legumes, and whole grains
Low carbohydrate diets already push you to limit any type of carbs but this study shows that it matters what carbs you get in your diet, even if there are not many of them. As for sources of plant protein that are low-carb friendly, here are some good options:
- Tempeh: 20 grams of protein and 7 grams of net carbs per 100 grams
- Nattō: 20 grams of protein and 7 grams of net carbs per 100 grams
- Edamame beans: 12 grams of protein and 4 grams of net carbs per 100 grams
- Tofu: 10 grams of protein and 1 gram of net carbs per 100 grams
- Black soybeans: 10 grams of protein and 1 gram of net carbs per 100 grams
- Hemp seeds, hulled: 25 grams of protein and 4 grams of net carbs per 1/2 cup (80 grams)
- Peanuts: 18 grams of protein and 9 grams of net carbs per 1/2 cup (72 grams)
- Almonds: 14 grams of protein and 6 grams of net carbs per 1/2 cup (64 grams)
- Tahini: 10 grams of protein and 8 grams of net carbs per 1/4 cup (60 grams)
- Lupini beans: 25 grams of protein and 11 grams of net carbs per 1 cup (166 grams)
- Lentils: 18 grams of protein and 24 grams of net carbs per 1 cup (200 grams)
- Pinto beans: 15 grams of protein and 25 grams of net carbs per 1 cup (170 grams)
When it comes to healthy fats, you should focus on sources high in mono-unsaturated fats and omega-3 fats and low in saturated fats. That means you can use plenty of olive oil, sesame oil, avocados, nuts, and seeds. Fish and seafood are also generally good sources of fats, especially omega-3s. At the same time, it helps to limit fatty cuts of meat, fatty pieces of cheese, heavy cream, lard, coconut, and palm oil.
