Failed Your Low-Carb Diet?! What Are the Reasons You Didn't Lose Weight?
A low-carb diet is highly popular because it seems easy: just cut down on carb-heavy staple foods, and you don't have to restrict meat or fish. However, while some see great results, others say they didn't lose any weight.
What causes someone to fail on a low-carb diet? Here, we explain the reasons behind unsuccessful weight loss, along with tips and precautions for doing it the right way.
Originally used as a dietary therapy for diabetic patients, the low-carb diet has recently become a mainstream weight-loss method. It is popular because it's easy to understand—simply avoid high-carb foods without the hassle of traditional calorie counting.
（１）Definition
Carbohydrates (or sugars) are abundant in staple foods like rice, bread, and noodles, as well as starchy vegetables and sugar. The American Diabetes Association defines a low-carb diet as consuming 130 grams or less of carbohydrates per day. For context, 100g of carbs is about two bowls of rice, two bowls of noodles, or four slices of bread. You can achieve this by skipping staple foods for two meals a day or reducing your portion sizes, especially at dinner when your energy expenditure is lower.
（２）How It Works
Restricting your carb intake prevents sharp spikes in your blood sugar levels after meals. Insulin, a hormone that lowers blood sugar, also has the function of converting excess sugar into stored fat, earning it the nickname "fat-storing hormone".
By limiting carbs, you suppress insulin secretion, making it harder for your body to store neutral fats. When your body is deprived of carbs, it activates a system called "gluconeogenesis" to create its own sugar energy. If your body depletes its sugar reserves, it breaks down neutral fats to create ketones for energy. This is the mechanism behind weight loss on a low-carb diet.
There are three main reasons why you might not be losing weight despite limiting your carbs:
Decreased Basal Metabolic Rate (BMR)
Consuming hidden carbs
Lack of exercise
Age, lifestyle habits, and a lack of knowledge about carbs can all hinder your weight loss.
（１） Decreased Basal Metabolic Rate (BMR)
Your BMR—the energy required to maintain basic life functions like breathing and body temperature—decreases with age. Looking at the standard BMR for average adults, a 50 kg woman in her 20s burns about 1,105 kcal at rest, but this drops to about 1,035 kcal by her 50s.
A higher BMR means you burn more calories, making it harder to gain weight even if you eat more. However, as your BMR decreases with age, you burn fewer calories, making weight loss difficult. Since muscles account for 20% of your BMR, muscle loss is a major factor. Continuing a strict low-carb diet can cause your body to break down muscle for energy (gluconeogenesis), lowering your BMR further. Therefore, it's crucial to maintain muscle mass through exercise.
（２） Consuming Foods
You Should Avoid Carbs aren't just in rice, bread, noodles, corn, or sweets. Starchy vegetables like potatoes, pumpkins, and lotus roots are also high in carbs.
Even seemingly healthy glass noodles (mien) are made from starch. Additionally, staple foods we eat daily like pho and banh mi, as well as sweet drinks like Vietnamese coffee with plenty of condensed milk, bubble milk tea, and chè (traditional Vietnamese desserts), contain a lot of sugar and require caution. If you drink alcohol, keep in mind that beer is high in carbs, so enjoy it in moderation.
（３） Lack of Exercise
Lack of exercise leads to muscle loss and a lower BMR, making it harder to lose weight even on a low-carb diet. To boost your BMR, you should incorporate strength training and increase your daily walking.
In daily life, motorbikes are the most common mode of transportation, but it is important to build a habit of moving your body even a little. For example, consciously take the stairs instead of the elevator, or walk to the neighborhood shops instead of riding. Research shows that increasing your average daily step count can boost your BMR and reduce body fat the following month.
BMR accounts for about 60% of your total daily energy expenditure. To boost it, you can:
Drink a glass of water or warm water when you wake up
Chew your food well and eat a balanced diet
Stay hydrated and practice abdominal breathing
Increase your physical activity
If you stay in an air-conditioned room for a long time, drink warm tea (like plain hot water) to warm up from the inside. Also, occasionally doing a warm foot bath during your shower is effective against the cold. Raising your body temperature by 1°C can boost your BMR by 13%.
（２）Get Enough Sleep
Aim for about 7 hours of sleep. During sleep, growth hormones that boost metabolism are secreted. Lack of sleep lowers metabolism and increases the secretion of ghrelin, a hormone that stimulates appetite.
（３）Balance Carbs and Protein
Don't cut carbs completely. Extreme restriction can cause your body to consume muscle mass for energy, lowering your metabolism and leading to rebound weight gain. Carbs also contain dietary fiber, which aids digestion and slows blood sugar spikes. Be sure to eat plenty of protein (meat, seafood, eggs, soybeans) as well, as it is key to boosting your body temperature and metabolism.
（４）Don't Let Stress Accumulate
Stress disrupts your autonomic nervous system and slows down metabolism. For carb-lovers, restricting favorite foods can be stressful and trigger binge eating. Find time to relax, listen to your favorite music, or get a massage to refresh yourself.
The average BMR is about 1,150 kcal for women and 1,500 kcal for men. If you consume fewer calories than your BMR, your body will adapt by lowering your metabolism, making it harder to lose weight and causing fatigue. Make sure you consume enough calories to support your activity level.
（２）Eat Breakfast
Within an Hour of Waking Up Never skip breakfast! Eating breakfast wakes up your brain and resets your biological clock. Skipping it lowers your metabolism and causes a sharp blood sugar spike at lunch. Studies show that people who skip breakfast are five times more likely to gain weight. Aim for a balanced meal with carbs and protein, like bread or rice with eggs, soy, or dairy.
（３）Have a Balanced Lunch
Eat lunch around 12:00 PM to 1:00 PM, when your stomach and liver are most active. It's okay to eat a hearty, balanced meal with protein, veggies, and carbs. If you crave high-fat or high-carb foods like fried dishes, ramen, or pasta, it's better to eat them at lunch rather than dinner.
（４）Finish Dinner by 9:00 PM
Focus on vegetables, mushrooms, and seaweed (rich in fiber), and keep carbs and fats low. Avoid eating late; between 10:00 PM and 2:00 AM, a protein called "BMAL1" promotes fat storage. Finish dinner by 9:00 PM. If you must work late, have a light snack (like a sandwich) around 7:00 PM, and a small, easily digestible meal when you get home. Skipping dinner entirely will cause your blood sugar to spike the next morning and make your body store fat out of starvation mode.
（５）Be Mindful of Alcohol
While distilled spirits (like whiskey and shochu) have zero carbs, brewed drinks like beer and wine do contain carbs. Sweet cocktails and plum wine are also high in sugar. If you choose to drink, opt for low-carb beverages.
If you're on a low-carb diet, supplements that gently block the absorption of sugar and fat can be a great support. Look for natural ingredients that inhibit sugar absorption, such as Salacia, Guava leaves, Gymnema, and fat-burning ingredients like Garcinia and Vitamin B. Enjoy your meals while managing your carbs smartly without being too hard on yourself.
６．Conclusion
A low-carb diet can be highly effective if you have the right knowledge and follow these tips. Don't be afraid of failure, and consider using helpful supplements to support your journey!
