During my early health-conscious years, I tried many different diets. Keto, intermittent fasting, carb backloading, paleo… you name it, chances are good I spent at least a little while trying to follow it. Although I lost weight on some of these diets, I also experienced dramatic and disruptive swings. I believe my problems with binge eating were exacerbated by following overly restrictive diets I could not maintain long-term. After one particularly rigorous diet, I also experienced adverse health effects that took me several months to truly recover from.
Lately, I’ve been getting a lot of questions about two popular diets, keto and intermittent fasting. With so many flashy messages and big promises, it’s easy to believe following one of these diets is the answer to your problems. But as with most things in health and fitness, the reality is a bit more complicated.
This week, I provide a brief overview of the keto diet and intermittent fasting. I explain how they work, why some people love them, and why they may not be a great fit for most people. Keep reading and keep an open mind below.
Keto
Although the idea of ketosis has been around for a long time, it has only recently gained popularity as a mainstream diet option. The keto diet goes a step further than other low carb diets such as the Atkins Diet or Paleo. The premise of this diet is that when we consume very low levels of carbohydrates, our body eventually runs of out of stored glucose (which our brains and bodies need for energy). It then converts stored body fat or dietary fat into glucose using a process called ketosis. According to proponents of the diet, once you enter ketosis you will burn stored body fat at a more rapid rate than before.
In order to get into ketosis, carbs need to be dramatically restricted for an extended period of time. This means removing foods like rice, oats, potatoes, and fruit and limiting vegetable consumption to small amounts of green, fibrous veggies. Protein consumption must also be reduced, because consuming too much protein can take you out of ketosis. The vast majority of your calories come from fat, which if done correctly, becomes the body’s primary source of fuel.
Some people do well on ketosis. These tend to be people who naturally feel best eating a higher fat, lower carb diet. These people report feeling more energized and focused when they’re in ketosis. They may also experience fewer cravings and more regulated hunger throughout the day. If you feel and perform your best with more carbs, however, you will likely feel like garbage following the keto diet.
Although keto is sometimes billed in the mainstream fitness media as a miracle cure, it has several notable downsides. It’s much trickier to get into ketosis and stay there than you may think; I’d be willing to bet many people who think they are following the keto diet are not truly in ketosis and are simply following a low carb diet. A single meal with too many carbs or too much protein can throw you out of ketosis. For example, I recently saw one of my Facebook friends sharing a photo of their “keto” meal which included a big fatty steak, broccoli, and a glass of wine. Between the protein in the steak and the carbs in the wine, this person was almost certainly not going to be in ketosis after their meal.
Additionally, keto is extremely difficult and impractical to maintain long-term. It’s tough to eat out at restaurants or attend social functions when you’re following such a restrictive plan. This is true even if you do feel good and see results following the diet. After a while, many people also find eating such a high quantity of fat becomes extremely unappetizing. So although keto may be working for you now, I definitely encourage you to find an exit strategy to transition back to a more realistic eating plan once you reach your goal.
Intermittent Fasting
Intermittent fasting (IF) is less of a diet than a meal timing strategy. For most of the day (including when you’re asleep), you fast and don’t consume any food or caloric beverages. The rest of the day, typically 8-10 hours, is designated as your feeding window. You consume however many meals and snacks you need for the day only during this window.
IF is a great option for people who naturally feel less hungry when they wake up. Instead of forcing themselves to eat breakfast when they aren’t hungry, these people can push back their first meal of the day to lunch time. As with keto, many people report feeling increased focus and mental clarity during their fasts.
However, IF is not a good option for everyone. If you have a history of disordered eating habits, IF can exacerbate your problems. For example, if you struggle with binge eating like I did, you may find yourself repeatedly eating way more food than you need during your eating window. Even if you have a good relationship with food, you may struggle doing IF if you have low energy without frequent meals earlier in the day. Additionally, men will typically have an easier time with IF than women due to hormonal differences.
One myth I hear all the time is if you fast most of the day, you can eat whatever you want and still lose weight. While this may be true for that rare person who is naturally able to regulate their portions, it is certainly not true for most people. I know from personal experience how easy it is to consume an entire day’s worth of calories at a single cheat meal when I’m hungry. Fasting doesn’t remove the need to monitor calories if your goal is to lose weight.
No Magic Pill
If you’ve followed my work for a while, you know I don’t believe in shortcuts. Attempting to circumvent the necessary time and hard work required to reach a worthwhile goal will only backfire and ultimately make it more challenging for you to get where you want to go.
Latching on to a fad diet because you think it will make it easier to get in shape is no different. Losing weight requires you to maintain a caloric deficit for an extended period of time. The keto diet works for people because they dramatically reduce the number of foods they can eat, which slashes calories. IF works for some people because they simply aren’t able to consume as many calories during their shortened feeding window.
Both diets can also fail to work if you still eat too many calories. Fat contains more than twice the calories per gram than carbs or protein, making it very easy to overeat. If you follow IF thinking it’s a way for you to eat whatever you want, you are sorely mistaken. It’s all too easy to blow your daily deficit by eating excessively large portions or tons of calorically dense junk food.
Ultimately, long-term success requires you to find an eating strategy that works well with your lifestyle. Your schedule, food preferences, and numerous other factors will all play a role. If you want to try a popular diet, go ahead! Understand that your success ultimately boils down to restricting calories in a sustainable, healthy way long enough to see results. This means navigating social situations, vacations, unexpected obligations, and stressful times at work. I believe seeking a middle ground will help you handle these situations with more grace and flexibility than a rigid, restrictive diet.
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