That said, there isn’t an agreement that a low-carb diet is superior to any other kind of diet or that it’s healthier long term. A review in the December 2015 issue of Diabetes Therapy that looked at the diet among those with diabetes noted that when it comes to weight loss, a low-carb diet performs no better than other higher-carb diets; and that it doesn’t produce better glycemic control, either. (5) Another report in Diabetes Care also found that over one year, those on a low-carb diet lost weight faster than those on a low-fat one, but after a year, weight loss and A1C levels (an average of blood glucose over about three months) were remarkably similar. (6)
Your body uses carbohydrates as its main fuel source. Complex carbohydrates (starches) are broken down into simple sugars during digestion. They're then absorbed into your bloodstream, where they're known as blood sugar (glucose). In general, natural complex carbohydrates are digested more slowly and they have less effect on blood sugar. Natural complex carbohydrates provide bulk and serve other body functions beyond fuel.
"Your body will often shift metabolism when you do something different to it -- but it equalizes -- you see a rapid shift and a return to normal -- and the longer-term studies show normal results in this area," says Sondike. Still, he tells WebMD it's a "smart idea" to take a calcium supplement beginning at the start of your low-carb diet to safeguard against a possible deficiency. Tofu can also be a good source of calcium.
Severely restricting carbohydrates to less than 0.7 ounces (20 grams) a day can result in a process called ketosis. Ketosis occurs when you don't have enough sugar (glucose) for energy, so your body breaks down stored fat, causing ketones to build up in your body. Side effects from ketosis can include nausea, headache, mental and physical fatigue, and bad breath.
Although oil or butter is high in calories, it is very slowly digested and surprisingly does not significantly increase your blood sugar. It makes vegetables taste better and can improve the absorption of certain vitamins and the essential vitamins A, D, E & K are only found in certain fats & oils. Avoid foods containing trans-fats (usually processed foods). Use oils such as olive oil, rapeseed oil or coconut oil. It also helps you feel full for longer so be more generous
If you’re looking for healthy low-carb snack ideas to bring on-the-go with you, your best bet is to make your own. Low-carb snacks you can prepare yourself at home — using low-carb foods like nuts, seeds, hummus, coconut flour or coconut oil, protein powders (like whey or bone broth), cocoa “energy bites,” cauliflower tots, and even low-carb “sweets” like cookies, muffins or donuts. And quickest of all are making up some low-carb protein shake recipes.
As for if you’re dealing with health issues, you really have to defer to your doctor. For instance, if you have kidney disease, you also want to talk to your doctor about appropriate protein intake. If you have heart disease, you can still go low carb, but you may be better off opting for monounsaturated fats (avocados, nuts, and olive oil) over saturated fats (butter and red meat). Everyone’s cholesterol levels respond differently on a low-carb diet, so if yours are going up, switch to unsaturated sources of fats, Spritzler recommends. “In general, this is a diet most people can do. If you have a chronic condition, work with a doctor who understands low-carbohydrate diets to monitor you,” she adds.
Once glucose enters your bloodstream, it causes your blood sugar to rise immediately. This prompts your pancreas to produce insulin, the hormone that allows glucose to move out of your blood and into your cells. How much your blood sugar goes up – and how long it stays elevated – depends on a number of factors, including how many carbs you eat, how much insulin you produce, and how sensitive your cells are to insulin.
Importantly, it is generally accepted that there is one component of carbs that isn’t digested and absorbed: fiber. This is because, unlike starch and sugar, your body lacks the enzymes needed to break down fiber. However, bacteria that live in your gut can digest it. After fiber passes into your colon, these gut bacteria ferment it into short-chain fatty acids, which don’t raise blood sugar and may provide health benefits.
If you have type 1, it's important to know that the best way to keep your blood sugar levels steady is to carb count rather than following a particular diet. And there is no strong evidence that following a low-carb diet is safe or beneficial, which is why we don’t recommend this diet for people with type 1 diabetes. But some people with type 1 have reported needing less insulin and losing weight from following a low-carb diet.