I wrote this article as I often get asked about which diet to follow. The below is based on my expert opinion as there is no one size fits all approach in nutrition. Our diets change as we adapt to our environment and our body grows. Having said this if any diets work for you and you can follow them long term and be in good health, good for you.
1. Juice Diets
This requires juicing fruit and vegetables to drink, or consuming ready-made juice drinks for the period of juicing. Typically most people sustain this for 2-3 days with the extreme being 1 week. If you are in a healthy state without blood sugar imbalances then it is easier to follow and gives the body a break from solid food. However this has to be carefully planned and it doesn’t suit everyone. The calories are reduced therefore hunger pangs, stomach pains, moodiness, headaches and changes in bowel functions are just a few of the side effects of the diet. Which may make certain focused and energy driven activities you are used to doing more difficult such as exercising. If not followed correctly or long term, it can lead to dis imbalances such as nutrient deficiencies. Fats, protein, vitamins and minerals that are not found in fruit and vegetables. The juices have to be balanced and fresh. When cutting out your favourite foods for a period of time, your cravings will grow, often resulting in an overeating phase following a juice diet.
2. Meal replacement shakes
Many ready prepared shakes contain artificial sweeteners, added sugars or ingredients that are not healthy. The vitamins and minerals added to ready made shakes are in minute amounts and no way comparable to levels found in foods. Shakes still contain calories and are not to replace food. The body thrives on solid food too as the teeth need to be exercised. Therefore chewing food is important to keep teeth strong. They have a purpose to bite and tear apart food. Chewing also gives the satisfaction of eating where this is bypassed if we are drinking our meals in liquid form! As a nutritionist I am for protein shakes to have in between meals or as a pre or post workout source of energy. They do work and help build muscle mass. However to replace breakfast, lunch or dinner with meal replacement shakes is not sustainable long term for the same reason as the juices. It is not the healthiest way to lose weight. Initially the weight loss lost is water weight and reduction of carbohydrates (rice, bread or pasta). Hence why the midriff appears slimmer. Again it’s impossible to get all the nutrients the body needs from shakes. Fibre from wholegrains, whole fruit and vegetables need to be consumed to keep the gut healthy and to prevent constipation.
3. Low calorie diets
Low calorie diets such as the Cambridge diet and other very low calorie diets under 1000kcals a day are also not sustainable long term and for weight loss. They can lead to binge eating episodes and may end up putting on more weight later than you began with as the body thinks its in starvation mode and slows the metabolism down. Furthermore they are not suited to everyone, for example if someone is regularly exercising their calorie expenditure will be higher and they need surplus calories for energy and refueling. Healthy weight gain is impossible without the right fuel and calories and without this muscle mass can decrease which is essential for health. Most people do not get enough nutrient calories as they are snacking of foods, which contain calories from carbs, but not much vitamins, minerals, fats and protein. This is to why calorie restriction leads to binge eating episodes, anytime of the day, not just in the evening. When the body is hungry it wants to be fed.
4. Low Carb diets
Cutting back on carbohydrates is not recommended for long-term health. Carbohydrates are an essential macronutrient group. Where individuals go off track with carbs, is they consume the wrong type of carbs, therefore refined carbs and sugars such as baked goods like cookies, doughnuts, ice cream, confectionary, syrups, and sugary soft drinks and juices. This is why weight gain occurs. However consuming wholesome carb foods as part of balanced diet such as oats, wholegrains, sourdough, pasta, beans and pulses for example gives the body and brain sustained energy. If carbs are dropped from the diet then this can impact strength and energy. As muscle glycogen is reduced causing fatigue which makes exercise and movement uncomfortable. Much of the weight loss on a low carb, high protein diet, especially in the first few weeks, is actually because of dehydration and muscle loss. Furthermore carbohydrates are important for serotonin production which keeps one in a happy mood. If you are following a high protein or keto diet then consider swapping to a hybrid diet where you include carbohydrates too. As all three macro nutrients are required for optimum health.
5. Vegan diet
The vegan trend is rising and a few years ago I was for veganism. After researching the diet in detail I have begun to question if this diet is also sustainable too. Although it comes with positive health benefits and weight loss. The diet has to be balanced and no food groups removed. If you are on this diet and having refined carbohydrates then you will not lose weight and will miss out on essential nutrients unless you are taking them in through nutrient rich superfoods or supplementing. Furthermore many vegan alternatives are also processed and not as healthy as they make out. Potential nutrient deficiencies are: vitamin D, iodine, iron, B12 and zinc.
6. 5:2 diets and intermittent fasting
Essentially they do work. But on the days where there is no limit on calorie restriction it can lead to over consuming calories that are often consumed by ‘bingeing’. It is better to eat consistently throughout the week then to have days where the calories are low and then back to normal as this can also trick the body’s metabolism. Every body is different so its about finding what works for you. Intermittent fasting works for most people as it provides windows of time in the day when food can be consumed and halts the calorie consumption to prevent over eating when unnecessary. However what is consumed is just as important as the timing it is consumed. Intermittent fasting of 16:8 hours and 14:10 hours seems to very popular and working for those currently following it.
