Working hard at a weight loss program without seeing results can feel devastating. Weight loss goes far deeper than calories in-calories out. It’s a complex hormonal game that involves regulation of thyroid hormones, cortisol, ghrelin and leptin (your “hunger hormones”), insulin, and even estrogen levels. If you’ve changed your diet, started an exercise program, maybe even bid adieu to sugar, but nothing’s budged on the scale, there are several reasons your hard work might be for nil.

7 Sneaky Reasons You’re Not Losing Weight

I want to start this post by mentioning that our body’s ideal weight may not match what society tells us is an ideal weight. This is especially true if you are a woman. Diet culture and society’s beauty standards are deeply ingrained in our beliefs about how our bodies should look. If you are in a medically normal weight range for your height, this post is not for you. This is a post for anyone who is clinically overweight and frustrated.

1) Hypothyroidism gets top billing because this is the most common issue I see with weight loss resistance. Your thyroid is the master gland in your endocrine system that is responsible for every single metabolic function on a cellular level in your body. That’s a fancy way of saying that it controls your breathing, hormone levels, fat burning metabolism, cognition, peristalsis, and energy levels.

If you thyroid is sluggish, the first thing you may notice is weight gain–even though nothing has changed with your diet–or inability to lose weight. Hair loss, constipation, and fatigue are also common. I always ask to see my clients’ lab work, and they’ll say, “My doctor said everything was normal.” Once I see the lab work, nine times out of ten, their thyroid numbers are well outside the optimal range, but they may be inside the reference range, so doctors won’t flag this until the numbers are abnormal, signaling there’s already a major problem.

ALWAYS request a copy of your labs, and look at your thyroid numbers. Your TSH should be under 2, preferably around 1.5-1.8. Your T4 and T3 should be in the top half of the upper range, with your free T3 at 3.0 or above ideally. If your thyroid is even a little sluggish, you won’t burn fat because your metabolism has slowed to a crawl.  I have had great success boosting thyroid function with this supplement that provides nutrients and amino acids needed to produce thyroid hormone. Read more about how to address hypothyroidism here. You can order your own thyroid labs here.

2) Your microbiome is mad. We are learning more and more about how the trillions of bacteria in our gut control every aspect of our physiology (even thyroid function). If you have more bad than good bacteria in your gut, the bad guys may be sabotaging your weight loss efforts by programming you to store more fat and by extracting more calories from food during digestion.

Bad bacteria in excess are obesogenic and inflammatory, and inflammation is also a weight loss blocker. If you’ve overused antibiotics, eaten too much sugar and too many refined carbs, used birth control pills, or taken acid blockers, your gut flora is way off kilter. You may need a program to heal your gut, and learn to properly nourish your microbiome. In this post I explain the connection between how gut bacteria influence your weight.

3) Lack of sleep can jack your cortisol levels, raising blood sugar and insulin, which increases fat storage. Poor sleep can drive cravings and make your hungrier, as it interferes with ghrelin and leptin signaling. Good sleep fights obesity. Learn how to get it.

4) Birth control pills can wreak havoc on gut flora and increase candida growth to unhealthy levels. The pill also contributes to estrogen dominance, which causes weight gain, increased appetite, and fluid retention. I am strongly anti-hormonal birth control for the above reasons. Read how to get off it here.

5) Eating too much… or too little. Eating too much, even if the right foods, will stall weight loss. I already mentioned that weight loss is more complex than calorie counting, but you do need to get an appropriate idea of what your intake should be. I recommend everyone calculate how many calories you need daily (based on your activity level, age, gender) and log everything you eat for a few days to help you get an idea of how much food you should be eating.

Eating too little (more common than you’d think!) is also a stress on the body, triggering fight or flight starvation mode where your body thinks “we’re in a famine! Gotta conserve energy!” And fat burning will be put on hold until your body perceives you are being adequately fed. It’s a brilliant design, really. Your body is trying to keep you alive and safe, so work with it!

6) Too much exercise… or too little. You want to lose weight, you gotta exercise. Exercise normalizes stress hormones and revs up fat burning. If you’re too fatigued, check your adrenals or see #1, hypothyroid. No exercise will stall your weight loss. (Vanity argument: exercise boosts growth hormone, making you look younger. And you’ll look better naked).

But too much exercise is perceived as a stress. I can’t tell you how many people have come to me during their marathon training complaining of weight gain. “I’m training for a marathon. How can I be gaining weight?” Stress = high cortisol = fat storage. Of course, you have to get moving, but there’s a sweet spot. Do 20 minutes of burst training at least twice a week, and 20 minutes of weights or yoga on the off days. 20 minutes!

7) Eating too low carb is a very common issue among the paleo women with whom I work. Women, listen up: Eating under 50 grams (or even under 100 grams) of carb can trash your thyroid hormone levels, especially T3, your active thyroid hormone. If you’re getting too little of a major food group, your body perceives this as starvation mode and slooooows everything down to conserve energy.

This is much more common in women than men; I theorize because fertility is a woman’s body’s main biologic goal, and if your body perceives a stress, it activates fight or flight mode, which means it’s not a safe environment to get pregnant. This is a main reason stress–diet-related or emotional–affects fertility. We all have a unique physiology and require different amounts of protein, fat, and carb. This post may help enlighten you about carbohydrate needs.

If you’re trying to lose weight unsuccessfully, get bloodwork with a thyroid panel and fasting glucose. Higher blood sugar levels will hinder weight loss (85 is ideal). Food sensitivities, most commonly to gluten, dairy, soy, corn, and eggs are also a common issue I see. Try an elimination diet.

Mary Vance (Certified Nutrition Consultant)

Mary Vance is a Certified Nutrition Consultant and author specializing in digestive health. She combines a science-based approach with natural therapies to rebalance the body. In addition to her 1:1 coaching, she offers courses to help you heal your gut and improve your health. Mary lives in San Francisco and Lake Tahoe in Northern California. Read more about her coaching practice here and her background here.