5 Ways Low-Calorie Diets Can Sabotage Your Health

By Caroline Kaufman, MS, RDN
Friends enjoying a picnic - 5 Ways Low-Calorie Diets Can Sabotage Your Health


To lose weight, you need to cut calories. So the more calories you cut, the more weight you'll lose and the healthier you'll be, right? Not so fast. If you eat too few calories, you put your health at risk in the following five ways.

You Won't Meet Your Nutrient Needs

It's easy to underestimate the significance of something you can't see or feel, but vitamins, minerals, fiber and other nutrients are just as important to your long-term well-being as the number on the scale.

For example, dietary calcium is important for both bone health and bodily functions such as muscle control and circulation. For the first 30 years of life, the body stores excess calcium in bones. After 30, you stop gaining bone mass and rely on existing stockpiles to keep your bones strong for the rest of your life. If you can't meet your calcium needs, your body is forced to "break open the piggy bank" and scavenge your bones for this crucial mineral. This process increases your risk for osteoporosis (thinning of the bones and loss of bone density) and hip fractures.

And, even with great planning, it can be difficult to get enough vitamin E, a fat-soluble vitamin found in foods such as nuts and oils, on a low-calorie diet. Vitamin E is an immune-booster and antioxidant that protects cells from free radical damage — the kind of damage that can cause cancer and chronic disease.

You'll Probably Gain the Weight Back

If you can't imagine eating so few calories for the rest of your life, you're setting yourself up to fail in the long term.

You Slow Your Metabolism

When you don't eat enough, your body goes into survival mode and starts breaking down muscle to release the glucose stored inside. Losing muscle mass can wreak havoc on your weight-loss goals because muscle burns calories 24/7, even if you are at rest. The less muscle you have, the fewer calories you burn.

You Lose Your Mental Edge

Your brain runs on glucose just like a car runs on gasoline, and it needs a constant supply to keep everything running smoothly. If you're hungry all day and running on fumes, you can't work at peak capacity.

You Might Get Gallstones

Very low-calorie diets (around 800 calories per day), cause rapid weight loss and increase the risk of gallstones, which may cause abdominal pain and require surgery.

How do you know how low is too low when it comes to cutting calories to lose weight? It depends on many factors that vary among individuals. To develop a healthful and effective weight-loss plan, consult with a registered dietitian nutritionist, who has the expertise to devise a nutrition plan tailored to your needs.

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