First, the portions are skewed — and not in your favor. “Protein portions tend to be too large, and vegetable portions too small, leading to an unbalanced meal,” says Alicia Romano, RD, clinical registered dietitian at the Frances Stern Nutrition Center at Tufts Medical Center in Boston.
Then there are the hidden ingredients that find their way in. “Added sauces or gravies can sneak in sources of carbohydrates from added sugars or flours that you were not intending to eat,” she says.
The reasons that you’re on the ketogenic diet — weight loss or perhaps a doctor-advised diet for a medical problem such as type 2 diabetes — also matters when choosing the best order for you. “The ketogenic diet can lead to successful weight loss, however it’s typically not necessary for most people,” says Jillian Kubala, RD, co-owner of Hamptons Clinical Nutrition in Southampton, New York. Although she says she finds the keto diet extremely restrictive (and therefore doesn’t recommend it), “the reality is that most people who are [on] keto are simply following a low-carb, high-protein diet,” Kubala says.
But that’s not necessarily a bad thing. This is what’s referred to as a “modified Atkins diet,” a less restrictive form of keto that counts carbohydrates but doesn’t restrict proteins, according to the Epilepsy Foundation. (Scientists originally developed a medical ketogenic diet as a treatment for children with epilepsy.) “If you’re following a ketogenic diet that falls in line with the modified Atkins diet approach, there’s much more flexibility with food choices, thus making eating out more reasonable,” says Romano.
There are several types of the keto diet and they all depend on strict macronutrient (carbs, fat, protein) calculations. Generally speaking, the medical keto diet used to treat epilepsy prescribes 3 to 4 grams (g) of fat for every 1 g of carbohydrate and protein, which means you’re getting 90 percent of your calories from fat, 6 percent from protein, and 4 percent from carbs, according to the Charlie Foundation for Ketogenic Therapies. A modified Atkins diet has no protein restriction, and ends up being comprised of about 65 percent fat, 30 percent protein, and 5 percent carbohydrates. When it comes to keto for weight loss, you might eat 70 to 80 percent of calories from fat, 10 to 20 percent from protein, and 5 to 10 percent from fat, according to the Harvard T.H. Chan School of Public Health.
Many people on keto use net carbs when measuring their carb intake. According to Atkins, you can calculate net carbs by taking total carbohydrates minus grams of fiber and sugar alcohols. The idea behind that, the company says, is that net carbs are what affect your blood sugar level and can compromise weight loss, so they, rather than total carbs, are worth counting. But you should know that neither the federal government nor the Academy of Nutrition and Dietetics recognizes this term, nor is calculating them an exact science, registered dietitians agree.
Also know that if you’re on a classic keto diet, you may need to connect with a registered dietitian to come up with a personalized plan for hitting more specific macronutrient targets, says Romano. Some people on this version of keto might measure ketones, which are a substance your body produces when it burns fat instead of carbs for fuel.