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Is Your Low Carb Diet Safe?


From time to time extremely dangerous diets catch on which pose danger to people's health. So to help you protect yourself against that, here are some tips about how to construct a healthy and effective low carb diet you can eat safely for years.


The key is to avoid going to extremes. Though extreme diets will produce rapid weight loss, they do so in ways that make your body fight even harder to put that weight back on. Slow and steady weight loss might not get you onto a TV show, but it is much more likely to make it possible to continue to fit into your skinny clothes years after you start your diet. Keep these principles in mind when deciding whether any low carb diet is a safe, sustainable diet:


1. A low carb diet should not be a high protein diet. Too much protein raises the amount of circulating insulin in your body and contributes to the stinky dragon breath that is such a common, and unfortunate, side effect of low carb dieting. Once you have eaten enough protein to repair your muscles and provide material from which the liver can synthesize the small amount of extra glucose your neurons may need when you are eating a very low carb diet, there's no need to eat more.


You can find out exactly how much protein you need to eat using our Low Carb Nutritional Calculator. It now lets you calculate how much protein you need to eat at any carbohydrate intake you might decide to diet at.


2. A Very Low Carb Diet Should Be a High Fat Diet. If you are eating a diet that provides less than 70 grams of carbohydrate a day--which for almost all people will be a ketogenic diet-most of the calories in your diet should be coming from fat. Fat, unlike protein, does NOT raise blood sugar or provoke any insulin response. Research has made it clear, too, that a high fat intake will not raise cholesterol unless it takes place along with a high intake of carbohydrates


The exception to the goodness of fats is trans fat. And despite all the labels that claim "no trans fat", any food that lists "hydrogenated" fats of any type on the label does contain trans fat. There are lots of them and you should avoid eating them.


3. A Low Carb Diet That Provides More than 110 grams of Carb a Day Should NOT Be A High Fat Diet My review of the research about low carb diets, conducted while writing my book, Diet 101: The Truth About Low Carb Diets brought home to me how important it is to remember that a high fat intake is only healthy when you are truly eating a very low carbohydrate diet. As your carbohydrate intake rises out of the ketogenic range (which extends from about 70 to 100 grams a day, depending on your body size) you must cut back on your fat intake. By the time your carbs have reached 150 grams a day, your fat intake should not be higher than 30% of total calories.


There are people who can eat a diet that is that high in carbohydrate without seeing unhealthy blood sugar spikes, but their diets are only healthy if they limit the amount of fat they eat along with that amount of fat. The Zone Diet is one diet that may provide that level of carbohydrate safely. But most people with abnormal blood sugars or diabetes will find it difficult to control their blood sugar with a carbohydrate intake that high. The Nutritional Calculator you'll find on this site uses this concept to recommend how much fat you should eat at various carbohydrate intake levels.


4. I've Reversed My Recommendations About Supplemental B Vitamins. It's traditional to recommend that people not eating grains should supplement with B vitamins. But over the past few years new data about B vitamin supplementation has made it clear that, as has been the case with so many other vitamins, B vitamin pills may actually worsen, not improve your health. Supplementation with B vitamins has been linked to increases in the speed at which kidneys deteriorate and to a higher risk of strokes.


If you don't eat grains, get your B vitamins from cheese, yogurt, and green vegetables.


5. Use Morton's Salt Substitute or Lite Salt to Replace Potassium. A low carb diet especially in its early phases flushes a lot of fluid out of your body. The diuretic effect can cause you to lose potassium and if that happens you may get leg cramps.


Sprinkling a bit of Morton's Salt Substitute on your food is all you need to do to correct any potassium imbalance--EXCEPT if you are taking a potassium sparing blood pressure medicine. These include some common medications including lisinopril. If you are taking a blood pressure medicine, ask your local pharmacist if it is one that makes it unsafe to use potassium instead of table salt. If it is, do NOT supplement with potassium.


If you are low in potassium, the usual symptom is leg cramping which resolves as soon as you consume a sprinkle of the salt substitute or lite salt. The first is pure potassium. The other is half table salt, half potassium. You can buy either at most supermarkets in the section where the salt is sold.


6. Eat LOTS of Greens and Berries. If you only eat meat and cheese on your "low carb" diet you are going to end up missing valuable nutrients. If you eat meat and greens and packaged "low carb" foods full of chemicals and hidden carbs, you are also going to miss out on those nutrients--and you are going to end up gaining weight, as many packaged foods include ingredients that are forms of MSG (like hydrolyzed vegetable protein) that make you hungry.


In the old days, people in the low carb community used to tell each other "When you visit the supermarket, Shop the edges" . That's because, typically, fruit, veggies, meat, nuts, eggs and dairy are arranged around the outside edge of the market and all the prepared foods are in the aisles. The more you eat from the edges, the healthier you will be. Frozen veggies are fine, too.


7. Don't Use Soy Protein. Many low carb recipes tell you to use soy flour. Don't. It tastes nasty to many of us, but a bigger concern is that soy can have negative effects on your thyroid and can disturb your sex hormone balance. Some people develop disturbing symptoms of depression when they eat too much soy protein. Whey protein powder tastes better than soy and has no hormonal effects. I use it in quite a few of my recipes. Vanilla or plain are best for cooking.


If you find yourself feeling depressive after a few weeks of your low carb diet, cut out any of the soy foods you may have added, including tortillas, "low carb" breads, or cereals. You may be amazed at how much cheerier you feel.


8. Don't Cut Your Calories Below 1000 a Day. Yes, you can lose weight by starving yourself, but do you really want to lose weight in a way that may damage your metabolism and make it impossible to maintain your weight loss?


The point of any weight loss diet is to learn a new way of eating that will be one you can sustain through the many years that follow your weight loss. The ugly secret, made crystal clear by all diet research, is that losing weight is easy, it's maintaining weight loss that's hard. And this is true no matter what diet you eat. The long term track record of low carb dieters in the years after they have achieved their weight losses is quite poor because our bodies do fight very hard to regain lost weight no matter what diet we use to lose it. So why worsen what are already poor odds by eating a starvation diet that makes it even more likely you will regain whatever weight you lose?


Starvation diets also raise the risk of developing nutritional deficiencies that harm your body. Worst case, they can unbalance your electrolytes in a way that can kill you.


The HGC diets is one such starvation diet, so is any very low carb/very low fat diet. These diets will cause dramatic weight loss for a brief period, but that period is followed by metabolic meltdown where your body cuts way back on the amount of calories it needs to maintain your weight while simultaneously raising the level of hormones that make you very hungry. The weight that comes back on is much harder to lose because you have slowed down your metabolism. Some research suggests this slow down is permanent. This was the experience of researchers saw happen to quite a few of the people who were weight loss stars on The Biggest Loser TV show, which also promotes extreme dieting.


Whatever diet your use, you need to avoid giving your brain the message that the food supply had contracted dramatically and that you are at risk of starving to death. Do that and your brain will do what it evolved to do over millennia--get you eating everything you can get your hands on to store up the fat you will need to survive the next period of famine.


8. Be Careful with Intermittent Fasting. Intermittent fasting diets like the 5:2 Diet are very popular now but most of us who have tried them for extended periods of time have learned they may have all the problems seen with other extreme diets, though they don't seem like starvation diets, as you can eat "normally" when not fasting.

Alternate day/5:2 Diets Work for a While and then Mess Up Your Metabolism

Encouraged by the success reported by some people I trust, I tested out eating a very strict 5:2 Fast Diet for two years. It took the whole two years for me to see the toll that this kind of dieting took on my body. During the two years I participated daily in an active online fasting-support group where I observed that the ultimately negative outcome I experienced was what most of the dedicated participants in the online group experienced: Very good weight loss results for the first seven months were followed by a sudden reversal where I first stalled and then then began to gain weight relentlessly eating exactly the way I'd been eating while losing so quickly. Worse, my appetite went out of control and by the end of the two years I had developed what felt like a binging disorder.


This was something I had never before experienced in decades of controlling my weight with various diet approaches, including 11 years of maintaining a substantial weight loss achieved eating a very low carb diet featuring occasional days off.


At the end of my 2 years of intermittent fasting I ended up with far more jiggly subcutaneous fat than I had started with, even though I ended up at the same weight I started at. I believe this happened because fasting lowered my estrogen levels dramatically. This was evidenced by my developing menopausal symptoms after a year on the diet--a decade after last experiencing them, at the same time as the diet had, indeed gotten rid of subcutaneous tummy fat.


It took me a good year to get back to having a normal relationship with my appetite. During that year I had to give up entirely on dieting in any way. The tummy fat seems to have moved in permanently. This experience was very much like what I saw others experience, too, including personal friends and people on the online support group.


To me this suggests that long-term intermittent fasting changes your brain chemistry and hormonal balance in a way that makes it much more likely that you will eventually run into this kind of problem.


If you are considering trying intermittent fasting be aware that all the research that is currently used to promote fasting by the usual suspects who get rich selling celebrity doctor diet books is based on very short studies which lasted only a few weeks or, at most, months. Almost all the studies on fasting looked at the physiological changes caused by very short stints of medically supervised complete fasting. Almost none examine the kinds of intermittent fasting dieters use in the currently popular diets like 5:2. The truth is, there is zero data about the long term experience of intermittent fasters.


The sad outcomes most people in my online fasting support forum experienced and my own results suggest that the outcomes over extended periods of time are mostly poor.


Eating a low carb intermittent fasting diet doesn't seem to produce better results, either, based on the reports of those on the fasting support group, who were eating that way. Those dieters stalled and regained on very low carb diets too.

If you do want to try this approach, take a break every three months and maintain your weight loss for another month by eating every day. It is possible that by doing this you may avoid this metabolic slowdown. 

Eating only Within a Limited Time Window May Be a Safer Approach

Eating only in a defined 8 hour period, for example, from 10 AM to 6 PM may be a better way to get some of the benefits claimed for fasting. It does not produce weight loss for many people, but it can stop the nighttime snacking that adds so many calories to people's diets. It also can help your body make the best of limited insulin stores. 

Non-Faddy, Moderate Low Carb Diets Won't Damage Metabolism and Can Produce Sustainable Weight Losses

My experience and that of many participants in online low carb diet support groups suggest that those who figure out a way to cut carbs in a way that doesn't make them feel deprived are able to stick to their diets for far longer with much better results and, most importantly, without the rebound hunger and metabolic slowdown that is so characteristic of more extreme diets.


It's worth noting, however, that my polling of those who ate low carb diets for extended periods after achieving weight loss goals showed that most of the successful dieters who did this maintained eating at a non-ketogenic intake level--one close to 110 g a day. It is possible that extended ketogenic dieting may also provoke the starvation response in some people.

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