Skipping breakfast. There are a lot of mixed messages about fasting (which is a whole different discussion) or eating breakfast, but the real answer is WHEN you choose to eat breakfast and WHAT it is you choose to eat. You can still fast 12-16 hours and still consume a nutritious breakfast. It's a great way to start your day because, your metabolism slows during sleep, and the best way to start up it up, is to eat in the morning - which will also set you up to burn more calories throughout the day! Think of it this way: When you consume breakfast, your body gets the message that there are plenty of other calories/sources of energy going to be had for the day. When you skip breakfast, your body thinks it needs to conserve energy, in order to get through the day. The same goes for skipping other meals as well!
Consuming non-nutritious meals/snacks OR a poor diet. It's not only important to eat every meal, but consuming a nutritious meal or snack is crucial as well! If you're consuming unhealthy options (sugary or fatty processed food), this will either lead to a crash or put you into a food coma - because of your body's glycemic response to the unhealthy food(s). You want to consume something that is a good source of all three macronutrients (protein, fat, and carbs). For example, a good option for breakfast would be: a full fat Greek yogurt (fat and protein source) - such as Fage Total 5% - fruit (carbs and fiber), and granola (carbs and fiber).
Not moving enough during the day. Say you have a job/career that causes you to sit all day, when you leave work you have to sit to drive, and when you get home you crash on the couch - all lead to a sedentary routine. A sedentary lifestyle can be detrimental to your metabolism. Your body things it needs to conserve energy and you also aren't engaging in any activity, also causing you to burn little to no energy. Set a reminder to get up and move every 1-2 hours at your job/career, engage in at least 30 minutes of moderate physical activity 3-5 days a week, and get rid of your couch ;) just kidding - but maybe Netflix, if you have an issue of binge watching shows/series.
Opting out of strength training. Sure, any exercise is great, but with strength training you are essentially building muscle mass (as long as you are performing exercises correctly, challenging yourself with each exercise, consuming the proper post-workout meal and consuming a nutritious diet overall). Muscle actually allows your body to burn more calories. The more active muscle mass you have, the higher your metabolic rate.
Not consuming enough protein. This ties into number 4. Protein is an essential building block when it comes to tissue repair - which is what your body needs after engaging in strength training exercises. Did you know that when engaging in a challenging strength training workout, you're actually causing microscopic tears in the muscle tissue? These tears need the proper nutrients/fuel to be repaired, which leads to building of more muscle mass! Also, protein is a macronutrient, which means we need a high number of our calories to come from high quality protein sources, to provide our body with the best for optimal health.
Not consuming enough water. A study published in The Journal of Clinical Endocrinology & Metabolism, found drinking 2 cups of water increased metabolic rate by 30%, and that spike lasted for more than one hour. So consuming water throughout the day, to stay hydrated nonetheless, will also boost your metabolism as well.
Stress. When stress levels are high, your body responds in a negative way. Cortisol levels are increased, leading to increased appetite, cravings for comfort food, decreased desire to exercise and reduced sleep and sleep quality - all things detrimental to your metabolism. While we can't always control our stress levels, learning how to manage your stress is important - for more reasons than just your metabolism.
Opting out of dairy consumption. According to research, people with the highest intake of milk, cheese, yogurt, and other dairy products, have the lowest rate of obesity. This is part of a growing body of research linking dietary calcium to improved regulation of energy metabolism. One reason dairy products may be known to boost metabolism is because, they are quality sources of protein and calcium - both promoting muscle mass, which can lead to weight loss (as you learned above, muscle mass burns more calories).
Not getting enough sleep. As I have discussed briefly before, sleep is essential for optimal health! Just one bad night's sleep is enough to lead to detrimental effects - lack of energy/motivation, impaired cognitive processing, and poor diet choices. As you can imagine, several nights of poor sleep can lead to a combination of issues effecting your overall health - more than just your metabolism. Research suggests 8-10 hours of sleep each night, in order to obtain optimal health!
Sleeping in a warm room. This may sound silly but a few research studies have found that sleeping in a cool room, can increase levels of brown fat (which burns calories to generate heat) and aid in a better nights rest as well. Research suggests that the ideal overnight temperature, is 66 degrees Fahrenheit.