What type of diet is best ?
The general approach to dieting...
Diet simply refers to the kinds of food you habitually consume. When we say diet, most people think about restricting yourself for the purpose of weight loss. Generally speaking, in order to lose weight, you have to calorie restrict (energy in must be less than energy out). When it comes to weight loss, most of us want a quick fix.
Unfortunately, that is never the right solution: this often leads to failure to sustain this "new" nutritional pattern, can be distressing on the body if extreme, and will typically result in re-gaining this excess weight. If fat loss is your goal, slow and steady wins the race! It's all about implementing a well-balanced diet while cutting out a few bad habits. This is also goes for those of you not wanting to lose weight.
Any restrictive diet that completely eliminates one entire group of macronutrients is generally not recommended.
Fats: Though fats historically gained a bad rep for its involvement in cardiovascular disease and atherosclerosis, it is an important source of energy. Fats are important for various physiologic processes including proper absorption of fat soluble vitamins. There are good fats and bad fats. The types of fats that should be avoided are saturated and trans fats which can not only increase your future risk for heart disease but can also negatively impact fertility (it increases insulin resistance and can result in ovulatory problems) (Kaipia et al, 1996). Meanwhile, polyunsaturated fats (PUFA) can be beneficial for your lipid profile, vascular function and is critical to reproductive function. PUFA is an essential precursor for steroid hormone synthesis (estrogen/progesterone), is needed to egg maturation and embryo development (Sturmey et al, 2009), and in implantation and supporting early pregnancy (Norwitz et al, 2001).
Sources of PUFA:
Microalgae supplements (Ginneken et al., 2011)
Carbs: The new "enemy" of weight loss. Many if not most weight loss plans promote a low carb diet. Though this is certainly one way to lose weight, it is not necessary. Remember, weight loss is a result of greater energy output than input (aka a caloric deficit), so you simply have to restrict. Like everything else in life, carbs in moderation can be extremely beneficial! It's not only the quantity of it but also the quality which can affect glucose metabolism and insulin sensitivity. Both blood glucose levels and insulin sensitivity play major roles in hormone balance and production in the ovaries and thus is highly linked to reproduction! Findings from the Nurse's health study II out of Harvard, demonstrated that higher glycemic load consumption resulted in higher risks of ovulatory dysfunction and infertility. This was particularly pronounced in women with PCOS when consuming high glycemic-index foods.
Whole grains however, actually boosted fertility! Whole grains are high in antioxidants/anti-inflammatory properties, and can improve blood sugar control and decrease insulin resistance which is highly linked with infertility (Agarwal et al, 2002).
Protein: Recommended daily protein intake is 0.8g/kg of body weight. For those getting into weight lifting, your dietary protein needs will certainly increase to 1-1.5g/kg especially when performing heavy lifting. In fact, women consuming up to 3.4g/kg/day have improved metabolic parameters and body composition (reduced abdominal fat and increased lean mass) without any adverse effects (Morenga et al., 2010; Antonio et al., 2015; Sørensen et al., 2012). Plant sources of protein have been found to be optimal for reproductive function, reduction in long term risk of cardiovascular disease and various cancers; not to mention it's great for the environment! Plant sources of protein have been shown to be protective of fertility and improves the body's hormonal milieu.
Dairy proteins: contains galactose which has been shown in various studies to impact egg quality demonstrated in both animal and human studies (Bandyopadhyay et al. 2003, Cramer et al, 1994) . Additionally, higher consumption of milk per capita was associated with a steeper decline in fertility with age (Cramer et al, 1994), as well as ovulatory problems; although these findings remain controversial based on contradicting results where dairy consumption did not impact fertility (Greenlee et al., 2003,Chavarro et al., 2007) more specifically, high fat dairy as opposed to low fat dairy which was associated with ovulatory dysfunction. Ultimately, though high quality data is lacking, minimizing dairy intake is likely to be beneficial with only modest amounts if desired.
Animal proteins: Animal proteins, particularly red meats, have been found to impact fertility in a number of mechanisms (including ovulation, endometrial receptivity for an implanting embryo, etc), though less evident with fish and eggs (Chavarro et al., 2008). Many animal proteins, particularly beef and pork contain high amounts of saturated fats, which if consumed in high amounts is not only is harmful to your cardiovascular health, but can impact ovulatory function based on long term prospective studies (Chavarro et al., 2007). Fish, though exposed to a number of environmental toxins, appears to remain beneficial due to its high source of omega-3 fatty acids and is linked to greater reproductive outcomes, including greater embryo quality (Braga et al., 2015).
Soy proteins: Soy remains controversial regarding its risk vs benefit. Like any other type of food, the source matters! A number of recent studies have shown that higher soy intake actually improves pregnancy rates, IVF outcomes and live birth rate. So it is unlikely to harm your fertility but may in fact improve it (Unfer et al., 2004; Unfer et al., 2004; Vanegas et al., 2015)! There are also a large number of studies indicating that soy intake reduces long term risk of breast cancer, contrary to popular belief (fritz et al., 2013; Jin He et al., 2013)!
In summary, nutrition is extremely difficult to study and to say definitely that consuming a particular food group is 100% bad. But your focus should be to have a well balanced diet, primarily composed of whole foods (mainly from plants) and some processed food is certainly ok!
I am personally plant based for both health and environmental reasons (there is large bodies of data indicating that animal proteins are generally not great for your health and tend to be inflammatory) but that doesn't mean if you consume small portions of animal protein and your meal is primarily focused on vegetables, legumes, fruits, and foods rich in anti-oxidants that you are "unhealthy"or that you will certainly end up various chronic diseases or infertility. The key is moderation here.
How to know your daily calorie requirements
Your daily caloric requirements depend on a number of factors including gender, height, weight, energy expenditure and desired amount of weight loss. Click this link to obtain a close estimate of your daily caloric needs.
Different medical societies recommend different ratios of all 3 macronutrients. The easiest approach is to first calculate your needed protein intake. Multiply the number of grams x 4 (cal) and subtract from your total daily calories. The remaining calories can be divided however you like between carbs vs fat (you can even play around with the proportions depending on what you wish to eat; ie if its high fat, lower your carbs and vice versa).
Keep in mind 1g fat = 9 kcal and 1g carbs = 4 kcal
For example: if I consume 1g protein/lb/day and my daily caloric requirement is 1800kcal; since I weight 125 lb and consume 125 g protein (125 x 4 = 500 kcal), I have 1300 kcal remaining. If i wish to divide them 50/50 then 650/9 = 72 grams fat and 700/4 = 162 g carbs.
Now, you do not need to count all your macros daily but it's not a bad idea to try it out for a week or two using apps like MyFitnessPal. It helps keep you accountable and realize how/what you're eating in a day. You'd really surprise yourself if you're honestly logging! We truly tend to over consume food!
If trying to lose weight, a healthy amount of weight loss is 1-2 lb/week. To lose 1lb in a week you must cut 3500 Calories (that's 500 per day). This is why fat loss takes time. For those going low carb and see a sudden drop in weight, this is simply water weight (since 1g carbs also carries ~3g of water with it) but does not represent fat loss. This is why as soon as carbs are consumed, that weight is regained.
Mindful eating is also a great tool once you understand the basics of nutrition. For many, logging every single food item and weighing it is too tedious and time consuming, but getting into the habit of always reading the nutrition information of all food labels can help you learn to estimate how much of each macronutrient you are consuming may significantly alter bad eating behaviors. By focusing on consuming whole foods, and reducing the amount of processed food you eat, it'll become much easier to control what goes into your body!
Mindful eating entails considering the nutritious value of the food you're about to eat, listening to your body (am I hungry and starving myself? or i'm full but it's so good i'll keep eating anything are things that should be avoided), eating slowly to gain a sense of fullness which could take some time for the brain to perceive and helps prevent over-eating and building a health relationship with food (void of guilt or anxiety regarding how it will affect your body, aesthetically speaking).
Following a well balanced, healthy diet doesn't have to be difficult. As a simply rule, 90% of your meals should be focused on plant proteins, some healthy fats and carbs and the other 10% of the time you can enjoy some treats! The idea is to modify your lifestyle and not feel deprived! Deprivation results in frustration and falling back into old/bad habits.