The skinny on fad diets

We're a few weeks into 2017...time for a New Year's resolution touch-base. One of the most popular resolutions is to lose weight. People try to achieve that goal in many different ways.

So here is the good news, most diets work. If you adhere to any weight management program, you will lose weight. If short term weight loss is your goal, the type of diet doesn't matter as each diet or program has one thing in common: restriction of calories either in the form of portions or elimination of certain foods. Cutting back or restricting food will yield weight loss. But, before you start counting calories in hopes of cutting 3,500 in a week to drop one pound, listen up. The latest metabolic literature shows us that there is much more to cutting that amount of calories per week. When you lose weight your body adapts, even if you don't lose any lean body mass, your metabolism will slow down. This means you need fewer calories to maintain your new weight and even fewer calories to lose more weight. It's not simple math!

There are so many diets out there it is hard to keep up! Most are not nutritionally-sound nor convenient. Here is the 411 on popular diet trends:

Low fat

Very popular in the 1990s, this diet demonizes fat of any kind. Low fat usually means an increase in carbohydrate consumption. Food companies took out the fat and replaced product with sugar. Don't you remember all those low fat snack foods that were insanely high in sugar? Not all fat is bad. While you want to limit saturated and trans fats, you do want to consume healthy fats like monounsaturated and poly unsaturated fats like those found in salmon, nuts, and avocado. These healthy fats help with satiety, blood sugar control, cardiovascular disease prevention and more.

Low carb

This diet was big in the 2000s. The breakdown is as follows: <40 % carb, 30% fat, 30% protein. Compared to low fat diet, the low carb may lead to great weight loss in first 6 months. But by 12 months, both the low fat diet and low carb diet yielded the same weight loss. The best-selling point is greater weight loss initially. Greater weight loss = better adherence = better success! The low carb diet is great for someone who doesn't want to count anything or do any math.

Intermittent fasting

This diet is based on fasting for certain hours or days of the week. The diet has you limit all food for 4-8 hours of the day. Very easy rules! Research shows it is easier to cut calories on some day versus cutting calories daily. Folks like it since you don't have to eliminate your favorite foods. Contrary to popular belief, we do not see folks over consuming calories on non-fasting days. The belief is that diet participants are in better touch with their hunger cues. Intermittent fasting is comparable to other calorie-cutting diets in regard to retaining lean body mass and fat loss, but there can be some not-so-lovely side effects. Issues with fasting can include: gout, urinary stones, abnormal heart rhythm, and a drop in blood pressure. Fasting is not recommended for athletes, those with medical issues, or the aging population.

Ketogenic Diet

Diet developed to treat epilepsy and seizures. This diet is 80-90% fat, 15% protein and <5% carbohydrate. The diet consists of mayonnaise, heavy cream, fatty steak with green leafy vegetables (easy because there are very few choices). YUM! I'm being facetious. How do you go to family functions or events? It is an extremely challenging diet to adhere too and very limiting. It's also low in key nutrients like fiber (understandably the side effect is constipation), calcium, vitamin D, iron, potassium and folic acid. Common side effects include headaches, fatigue, bad breath, grouchy and leaky gut (loosened intestinal gaps in intestinal lining). After about 7 days, you rely solely on ketones, formed from fat breakdown for energy, and it takes about a month to fully adapt. That being said, you will see immediate weight loss! It's all water as you are depleting your glycogen stores, so the second you stop this diet, you gain weight as you are reintroducing carbs back into your life. Your cholesterol and LDL elevate and arteries stiffen which can affect blood pressure. As a registered dietitian, I am still baffled that this is still a thing.

Whole 30/Paleo

This diet eliminates entire food groups - grains, dairy and legumes - which can cause you to become deficient in calcium, iron, b vitamins and vitamin D. Legumes are also among the foods highest in fiber. The rules of Whole 30/Paleo are easy to understand and socially this is a "cool diet". But a red flag should go up anytime an entire food group is "off limits".

Detox diets and cleanses

Want to annoy a dietitian? Mention these words. You don't need to detox or cleanse. Your body does this for you thanks to your kidneys and liver! This diet can be full of laxatives and diuretics so you are in the bathroom...a lot. Juice cleanses are very high in sugar so this is a nightmare for someone who is diabetic or prediabetic.

Meal replacements

On this diet, you replace one to two meals with a shake or prepackaged meal. Of course you lose weight as you are restricting calories. In addition to weight, you also lose lean body mass. Less lean body mass can mean a slower metabolism. Like the ketogenic diet, this diet is socially challenging because you cannot eat with loved ones.

If It Fits Your Macros "IIFYM"

Similar to carb counting or Weight Watchers®, this diet is point-counting. You have to count and log so the diet does involve more thinking. It's a lot of meal prepping and eating the same foods daily. You will lose weight on this diet as you are restricting calories, and it yields similar results to other diets. "IIFYM" has the potential to be successful over time as it allows for all food groups in moderation, but be careful not to fall into the trap of making unhealthy choices, just because they fit.

Long story short, all of the above diets help you lose weight and have the potential to be successful over time because they allow for all food groups in moderation. And, we have study after study that shows losing weight is going to improve your health! As a dietitian, I recommend eating a variety of foods in small portions throughout the day. I promote healthy carbs (fruit, whole grains, low fat dairy), lean protein and healthy fats (olive oil, fatty fish, nuts and avocados). I encourage my clients to enjoy all vegetables and to enjoy their food! My goal is to show people eating healthy is a lifestyle, a long term solution versus quick, fast weight loss that will most likely reappear.