Hi folks,
I recently found this sub-reddit and thought I would lend a hand by discussing some of the basics of nutrition for weight loss. I am currently doing my PhD in performance nutrition. I have an MSc in Human Nutrition with specialization in Sport & Exercise Nutrition and have spent numerous years in the field. Here I will cover some of the basics of nutrition for weight loss.
Energy Balance
As many of you are aware, weight loss is a product of being in a consistent energy balance. This means consuming less (kilo)calories than our bodies expend. We get energy from the food and drink we consume and we use energy maintaining our bodies functions (known as Basal Metabolic Rate), moving around our day to day lives (walking, fidgeting) and via physical activity.
If weight loss is your goal, you’re going to want to slightly REDUCE the energy in and INCREASE the energy out. Simple things like walking up stairs instead of talking the lift can help this.
Although you don't need to track calories to lose weight, you do need to be in an energy deficit. Some people like to put themselves in a deficit by lowering carbohydrates, some like to track calories, some like to lower dietary fats - they are all tools in the toolbox to achieve the goal of weight loss.
Although it isn't for everyone, I personally like to track my caloric intake when i am dieting down. Humans are pretty poor at accurately tracking their energy intake however consistent tracking and monitoring weight loss (visually, using the scale and measurements combined are a good way to do so) will allow you to identify whether you're eating appropriately for your goal
Diet Quality
A lot of people talk about weight loss as calories in vs. calories out, which is kinda correct but also very reductionist thinking. Diet quality is of major importance because if you are deficient in nutrients your body requires, you run the risk of impairing your physical and cognitive performance or damaging your health. Eating in a slight energy deficit (300-500 calories below your maintenance) and consuming a wide variety of nutrient-dense foods (fruit, vegetables, dairy, lean meats, fish, whole-grains, nuts, seeds and pulses) will help ensure you remain nutrient-sufficient. A high-quality diet is important not only for ensuring nutritional adequacy. It also provides dietary fibre and phytonutrients, which aren’t essential but is very beneficial for health as they’re associated with lower risk of cardiovascular disease, T2 diabetes, certain cancers and coronary heart disease.
They will also promote weight loss because the fibre provides satiety. Fruit and veg are also very volumous for their energy content, and eating a lot of veg will physically push against the stomach (gastric distention) which signals to your body that you are satiated. More information on these can be found here - https://www.youtube.com/watch?v=gpbk--mRXOQ
Protein Intake
The most important macronutrient. I am biased because my PhD research is in this area but that is because protein is so diverse. Whilst carbohydrates and fats primary function is to provide fuel for our bodies metabolic functions, proteins have many other roles. They can be used as fuel in times of starvation. They provide structure, stability and function (think muscle proteins). They allow us to transport molecules around the body (haemoglobin is a protein that is involved in oxygen transport). They act as signalling molecules (hormones), they catalyse biochemical reactions in the body (enzymes) amongst many other functions.
Protein is particularly important for weight loss for a number of reasons. It will help preserve lean muscle mass, which will ultimately improve body composition. Protein is more satiating than carbs or fats, meaning it will promote fullness. Protein is also very thermogenic, with around 25% of the energy contained within protein ultimately acting to digest, absorb and metabolise the nutrients.
Protein from lean meats, fish and dairy will provide all 9 essential amino acids (they must be obtained from the diet). Soy and mycoprotein-containing ‘fake meats’ also contain all 9 essential amino acids. Other proteins from veg-friendly sources are typically lacking in one essential amino acid however a varied intake of these sources will allow for all 9 to be consumed.
Aim to eat between 1.2-2.6 grams of protein per kg of bodywight per day. So an 80kg person should aim for between 96g and 208g per day (I would certainly advise going to the higher end if weight loss is the goal).
Meal Timing
Meal timing is a hot topic. Some folk say you should eat once per day, some people reckon 7 meals a day is the holy grail. The truth is, purely from a weight loss perspective, how you distribute your meals is up to you. If you prefer intermittent fasting until 3pm and eating all of your food in the evening, go for it as long as you stay in an energy deficit.
Protein intake spread throughout the day might be more optimal for preserving muscle mass. Our muscles are built and maintained when in a positive protein balance – when synthesis exceeds breakdown. Protein feeding (and exercise) increases synthesis. Fasting increases breakdown. If you eat protein spread throughout the day then theoretically you would maintain more muscle during weight loss. The research is in its infancy so I cannot say for sure however I do spread my protein intake throughout the day to be on the safe side.
Spot Reduction
This is a question I’ve seen raised a lot here. People want to know what exercises will burn certain types of fat (belly, man boobs etc). I am sorry to say that you CANNOT spot reduce fat. Your genetics determine where your body mobilised fat stores from (so blame your parents lol!). Males typically store their fat around the waist and lower back and females around the hips (think child-bearing). It is unfortunate but the reality is if you have a problem area of fat then you just need to keep grinding and reducing your body fat. Some people can get extremely lean in certain areas before other areas start to reduce the body fat.
Bad Foods for Weight Loss
There are no bad foods for weight loss on their own – you need to consider the wider diet. Weight loss isn’t just an acute process – it is something which occurs over many months. Rather than thinking about your food intake over a day, think about it over a week. One McDonalds meal in a week will amount to around 4-8% of your total food intake. If this isn’t displacing the nutrient-dense foods in your diet then this is perfectly fine and might actually be beneficial at allowing you to adhere to a weight loss regimen. If you eat one McDonalds meal a day ten you could still be in an energy deficit but you’d be likely to displace nutrient-dense foods as this now accounts for 25-30% of your total food intake. I say there are no good or bad foods, just good or bad dietary patterns!
Hydration
Water intake is crucial for healthy living. We are around 60% water – our blood is mainly water, or joints are lubricated by water, water is the medium which all biochemical reactions occur in our bodies..you get the idea of how important it is! A lot of the time we mistake thirst cues for hunger cues, so drinking water may offset some unwanted snacking. Slight decrements in body water (2% bodyweight) can impair exercise performance so inadequate hydration might mean you can’t exercise to a decent intensity.
That is all I can think of now. I will do another post about nutrition for muscle building soon. If you have any questions feel free to ask!
