Two Biological Reasons Why Low Carb Diets Don't Work

Low-carb diets reduce or eliminate carb intake. Most Americans get plenty of carbs from breakfast cereals, toast, bagels, muffins, sandwiches, potatoes, pasta, salty snack chips and baked desserts throughout the day. The 2010 Dietary Guidelines for Americans recommend that 45 to 65 percent of your calories be provided by carbs, and a carb calorie intake below 40 percent is considered low-carb. If you do not have any success trying to lose weight eating low-carb, it might be tied to biology.

Carb Intake

Low-carb diets are not clearly defined, and any diet providing less than 40 percent of your calories from carbs is considered low in carbs, which could correspond to about 20 to 200 g of carbs a day, based on a 2,000-calorie diet. Everyone has a different and individual tolerance to carbs, and what works for another low-carb dieter might not work for you. If your low-carb diet plan is not producing the results you seek, you might be eating more carbs than your body can handle. If you eat too many carbs, it stimulates the release of insulin, one of the main hormones involved in fat storage.

Finding Your Optimal Carb Intake

To ensure your carb intake is appropriate for you and keeps your insulin levels low to promote fat loss, you need to find your optimal carb intake. For active people, 150 g of carbs a day might work well, while others might need to stick to 35 g of carbs a day. Your carb tolerance is probably very low if you have a lot of weight to lose; are diagnosed with prediabetes, diabetes or metabolic syndrome; have yo-yo dieted in the past or are simply not as young as you used to be. Try lowering your carb intake to a specific level, whether you choose to start with 100 g a day or 50 g a day. At the end of the week, see how your weight changes. If it is still not working, lower your carb intake by another 10 to 20 g or until you find the optimal amount of carbs that works for you. Make sure you count your carbs accurately and consult your doctor or dietitian for guidance.

Stress and Cortisol

Stress can interfere with your weight loss efforts and is the second biological reason that could hinder your weight loss efforts on your low-carb diet. Whenever you feel stress, whether it is due to stress in your social life or at work, a lack of sleep or the stress associated with not losing weight, your body releases a stress hormone called cortisol, which promotes a metabolic pathway called gluconeogenesis, a process that allows your body to produce sugar from protein and fat, as explained in "Clinical Science." Even if you are limiting your sugar and carb intake, your stress can make your blood sugar levels and insulin levels increase, which could hinder your weight loss.

Control Your Stress

If stress is a big part of your life, you will need to find ways to relax if you want your low-carb diet to work. Start by sleeping at least seven to eight hours a night and eliminating stress triggers that you can easily remove from your life. For example, if you always stress about arriving in time at work, leave 15 to 20 minutes earlier to arrive more relaxed. Include some deep breathing, yoga or walks outside during your lunch break to help you relax. Most Americans are always rushing from one activity to the next, which can be very stressful. Allow yourself the right to take time for yourself and just read a book or enjoy your favorite hobby. Finally, stop stressing about your weight and do not step on the scale every day. Put the scale away and weigh yourself no more than once a week.