Vegan Protein for Successful Fat Loss
By Pete Ryan
If you eat a well balanced diet, then you can get enough of every nutrient, whether you are trying to gain weight, maintain, or lose fat.
This is a factually true statement, but the answer, although factually accurate, fails for many people in practice.
Most of us do not have hours to spend in food preparation, or even if we do, we do not have the culinary skills to achieve these ideals. For most people living in the modern world, food is eaten ‘on the fly’. We have little control over how restaurants prepare foods and what there is available when we need it.
The problem is that when we need to lose fat we are trying to balance many factors that often seem contradictory. Two of the hardest to balance are the twin goals of lowering calories & raising protein. Many people do not even know you should be aiming at both of these goals & those that do often have a hard job managing to achieve both.
Why should we consider raising protein while lowering calories when we want to lose fat?
Let’s first look at why you should be aiming at lowering calories & raising protein when you try to lose fat. There are several reasons involving mechanical functioning of the gut, hormones, muscle sparing & metabolic issues. We will look at all of these & see why it would be advantageous to increase protein while lowering fat compared to other systems you may have read about.
This is the easiest to understand. Protein makes you feel satisfied more quickly & for longer when eating[i] , than eating carbohydrates or fats. To feel satisfied for longest including some high protein food will help stop you feeling hungry. Proteins from all sources seem to trigger this same effect of satisfying hunger[ii], whether from food or from powder.
As hunger is the number one reason for failure at a diet, then it makes sense to include higher protein sources to avoid this potential pitfall.
Thermic Effect of Food (TEF)
All food takes energy to digest it. Fats, carbohydrates, proteins & alcohols all use up calories just to be assimilated & utilised by the body. Alcohol is the most thermic food, that is, it uses the most calories during digestion & assimilation. Unfortunately, an alcohol-focussed diet has several drawbacks to overall body composition, health & daily functioning.
The macronutrient that takes most energy to digest after alcohol is protein. Protein costs the body more calories to digest than either carbohydrates or fats[iii]. This is good when you are attempting to lose fat as you can eat more calories of a protein food compared to either of the two other macronutrients. So, it makes sense you should try to eat a generous amount of protein as you can have more calories per meal.
Slowing Carbohydrate Assimilation
Protein slows the assimilation of carbohydrates into the blood[iv]. This means that you are much less likely to get the sugar highs and lows you can get by eating carbohydrates alone. It is this blood-sugar rollercoaster, the sudden sugar high, then corresponding low that often drives people to inappropriate eating & fat gains due to the constant need to snack on sugary foods. Put simply, without protein, a mainly carbohydrate meal will enter the bloodstream very quickly. This is cause a huge surge in sugar production to shunt the carbohydrates into glycogen storage, or to be stored as fat. The body often causes excessive sugar production to be produced and so blood sugar actually dips too low after the initial high. This sets the stage for increased hunger & to repeat the cycle. So you get the hunger, the snacking on sugary foods the high, then the crash, which inducing a hunger response & to repeat the whole cycle over & over throughout the day.
If however you include some protein into a meal or snack, you slow gastric emptying. This stops the excessive sugar high from occurring & also prolongs a slower trickle of energy that lasts longer. So, you get less of an initial sugar ‘hit’, sugar production stays lower, no crash and sustained release of energy over time. All this will keep you feeling fuller lower & keep hunger at bay between meals.
Maintaining Muscle Mass as you Diet
If you are dieting why should you care about muscle mass? Most people when they diet aim at a ‘weight’ they want to achieve. This is actually a poor method of achieving a lasting goal. A better method is to aim at a bodyfat percentage. Weight within reason doesn’t matter, it is the muscle to fat ratio that is really important. Why is the amount of muscle important for sustained fatloss? Muscle is the furnace of the body 24 hours a day, 7 days a week muscle needs fuel just to keep it there. Fat, bones, connective tissue need very little energy to maintain them, whereas muscle needs a whole lot of energy just to keep it. When we say ‘energy’, we are talking about calories. Muscles burn calories just by being there. When you see people starving you’ll notice they have virtually zero muscle. When you diet, unless you actively fight against the process the body will drop muscle very quickly. Why does this matter?
So, let’s look at the average female in the US[v]. The average US female weighs 11 stone 12lbs (166.2lbs or 75.35Kg). Most woman have muscle mass of between 28% and 39% so let’s say a US female has 35% lean muscle mass, so they have approx 4 stone 1lbs (57lbs or 26Kg) of muscle mass. She needs 2,500Kcal to maintain her weight. She drops her calories to lose fat, but does not try to preserve muscle mass while she diets (does not do some form of resistance training & keep her protein intake up). After a while she may reach 10 stone (140lbs or 63.5Kg), but this could look very different between individuals. In one individual the 10 Stone could mean a some fat loss and much muscle loss, while in the other the percentage of muscle could be maintained (or even increased – this increase is only relative as the body has shed a lot of fat, but lost only a little muscle, so although you have less muscle the percentage compared to fat has increased). The woman in the example above may have reach 10 stone, but only has 3 stone (42lbs or 19Kg) of muscle, while another that ate high enough protein & resistance trained has maintained 3 stone 8lbs (50lbs or 22.7Kg) of muscle. Not only will the woman with the most muscle look better, but she will be able to eat a lot more calories once the diet has finished and the ideal weight is achieved. This is because muscle uses calories and so you will need to eat more just to keep that muscle working. Meanwhile the woman with the least muscle will be more likely to have that ‘skinny-fat’ look that you want to avoid & will probably end up adding bodyfat as the calories creep up once the diet finishes.
Low protein and muscle loss
So, we have seen how muscle aids you in a diet by burning extra calories, now let us look at what happens when you keep calories identical, but use a lower protein diet. With a lower protein diet, even if the calorie decrease is identical, then you tend to lose more muscle mass[vi]. Because keeping as much lean muscle as possible means that maintaining a healthy bodyfat leavel is much easier, the best solution is to attempt to keep protein levels relatively high when you diet (& participate in some form of resistance exercise programme).
Plant protein inferior to animal protein?
For the longest time gym-lore assured us that plant protein was inferior to animal protein. This idea was parroted by nutritionists and the medical community. Whey protein was considered the best protein by many strength athletes. Recently researchers have begun to question this assumption. In one study they decided to compare rice protein with whey protein head to head. The results were that the muscle gains between rice protein and whey protein was identical[vii]. There have also been studies with products like wheat protein, which concludes that increasing the amino acid L- leucine content equalises the muscle building effects of that protein[viii]. So, it is clear that plant protein can be as anabolic as their animal-based alternatives, the main issues appear to be the quantity of protein consumed and allowing time for the body to adapt to new protein sources (by altering the gut bacterial composition and enzymes produced within the gut).
Benefits of plant protein over animal proteins
We have now established that plant-protein is equally effective to animal protein (given that the body has had time to adapt to the new diet). Assuming that is the case can plant protein have a beneficial effect upon the body beyond aiding increased hypertrophy or sparing lean muscle tissue when dieting? Several studies have begun to explore the idea that whereas animal proteins may tax the kidneys due to an overabundance of sulphur-containing amino acids[ix],many plant proteins appear to actually renal-protective[x]. So, it seems that plant proteins may be a wiser choice for many people who value long-term renal health.
Bringing things together
There is no ideal to bring this all together. What is possible for one person may not be possible for others. I usually suggest that someone dieting have in their favourite protein powder as an insurance. Having a shake as a snack or with a light meal can make the difference between a successful diet & just another yo-yo of weight loss followed by fat gain. For most people I have found that around 2g/Kg (0.91g/lb) of protein works best for maintaining muscle mass while losing fat.
The things to have in place for successful fat loss are:
- Having a calorie controlled diet.
- Introduction or continuation of a resistance exercise programme and the inclusion of enough protein to satiate and stop muscle loss induced by fat loss.
- A diet that allows for satiation and one that increases the thermic effect of Food (TEF).
- Insure you are eating around 2g/Kg (0.91g/lb) of protein daily.
Only a higher protein, lower calorie diet fulfills all these needs[xi],[xii]. You can diet other ways, but in my view & from the research out there this method is the most likely to succeed over the longer term as you keep your calorific needs high, while losing fat. Keeping the calorie needs as high as possible insures that when you return to a more balanced eating plan the fat will stay off & you will enjoy a fitter, leaner body for many years.
[i] Ortinau, LC, et al. Effects of high-protein vs. high- fat snacks on appetite control, satiety, and eating initiation in healthy women. Nutrition Journal 2014, 13:97. http://www.nutritionj.com/content/13/1/97
[ii] Overduin J, et al. NUTRALYS(®) pea protein: characterization of in vitro gastric digestion and in vivo gastrointestinal peptide responses relevant to satiety. Food Nutr Res. 2015 Apr 13;59:25622. http://www.ncbi.nlm.nih.gov/pubmed/25882536
[iii] Westerterp, KR. Diet induced thermogenesis. Nutrition & Metabolism 2004, 1:5. http://www.nutritionandmetabolism.com/content/1/1/5
[iv] Karamanlis A, et al. Effects of protein on glycemic and incretin responses and gastric emptying after oral glucose in healthy subjects. Am J Clin Nutr. 2007 Nov;86(5):1364-8. http://www.ncbi.nlm.nih.gov/pubmed/17991647
[v] Ogden, CL, et al. Mean Body Weight, Height, and Body Mass Index, United States 1960–2002. CDC Advanced data, Number 347, October 27, 2004. http://www.cdc.gov/nchs/data/ad/ad347.pdf
[vi] Bopp, MJ. Et al. Lean Mass Loss Is Associated with Low Protein Intake during Dietary-Induced Weight Loss in Postmenopausal Women. J Am Diet Assoc. 2008 Jul; 108(7): 1216–1220. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3665330/
[vii] Jordan, MJ, et al. The effects of 8 weeks of whey or rice protein supplementation on body composition and exercise performance.Nutr J. 2013; 12: 86. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3698202/
[viii] Norton LE, et al. Leucine content of dietary proteins is a determinant of postprandial skeletal muscle protein synthesis in adult rats. Nutrition & Metabolism2012,9:67. http://www.nutritionandmetabolism.com/content/pdf/1743-7075-9-67.pdf
[ix] Veldhorst M, et al. Protein-induced satiety: Effects and mechanisms of different proteins. Physiology & Behavior, Volume 94, Issue 2, 23 May 2008, Pages 300–307. http://www.sciencedirect.com/science/article/pii/S003193840800005X
[x] Aukema HM, et al. Distinctive effects of plant protein sources on renal disease progression and associated cardiac hypertrophy in experimental kidney disease.Mol Nutr Food Res. 2011 Jul;55(7):1044-51. http://www.ncbi.nlm.nih.gov/pubmed/21294251
[xi] Paddon-Jones D, et al. Protein, weight management, and satiety. Am J Clin Nutr. 2008 May;87(5):1558S-1561S. http://www.ncbi.nlm.nih.gov/pubmed/18469287
[xii] Westerterp-Plantenga MS. Et al. Dietary protein – its role in satiety, energetics, weight loss and health. Br J Nutr. 2012 Aug;108 Suppl 2:S105-12. http://www.ncbi.nlm.nih.gov/pubmed/23107521