this tends to allow much of the food flexibility and such that small deficit diets have as one of their pros; the diet only has to be changed minimally to achieve the necessary deficit. Even there, moderate deficit dieting does feel like more of a diet than small deficit dieting, the individual will feel more restricted overall (unless they create the entire deficit through activity).
For athletes and performance types, this is a benefit since it tends to have a small impact on gym or sports training. This is especially true if concepts such as the refeeds and full diet breaks discussed on the site and in my are adhered to.
Of course, since the fat loss is faster, the diet tends to get finished quicker. While some larger individuals with a lot of weight to lose may still find the prospect of dieting for a year to be overwhelming, at least things will be happening a lot more quickly than with small deficits.
In terms of screwing up, it certainly is possible to offset some of the deficit of a moderate fat loss diet with mis-measurement but it’s far harder to eliminate the deficit completely. It can be done, make no mistake about it, but its relatively more difficult (what usually happens is that an expected 500 cal/day deficit ends up around 250-300 cal/day and people wonder why the fat loss is only half what it should be).
Metabolically, moderate deficit dieting does have an impact for reasons i’ve discussed endlessly on the site and in my books and won’t discuss again here. But between the rate of fat loss and impact of caloric restriction on hormones like leptin, etc. There’s no getting around the fact that the body will fight back to some degree with moderate deficit dieting (realistically: This will happen on any diet no matter what you do).
Frankly, outside of the fact that moderate deficit dieting may take really extended periods for very overfat individuals, i’d probably say it has the fewest overall cons relative to the potential pros. Which is probably why it tends to be one of the most widely recommended and used approaches.
Of course, some people are still impatient (or have their own reasons for wanting or needing) faster fat loss and the moderate fat loss of the moderate deficit can be both a pro and a con in that regard. And that brings us to large deficit dieting.
large deficit dieting: 25% below maintenance or greater
while i’m going to define large deficit dieting as anything greater than 25% below maintenance, for the sake of this discussion, i’m actually going ot use a massive deficit: A full 50% below maintenance. Just to illustrate the point.
I actually advocated this size deficit in the first phase of my but it’s also only for 4 days. actually revolves around protein intake rather than caloric intake per se but,on average, the deficit may end up at 50% below maintenance or even more. So that’s why i’m going to use 50% for this illustration.
Dieter-----maintenance cals---------total deficit--------estimated fat loss
female----------2000 cal-------------1000 cal---------2 lbs. Per week
male-------------2700 cal-------------1350 cal---------2.7 lbs. Per week
i’d note that for very large individuals, with high maintenance caloric expenditures, greater rates of fat loss are possible with one-half to two-thirds of fat loss per day being possible when calories are low enough.
Now, clearly the biggest pro (to some) of this approach is that the rate of fat loss is maximal. Even our smaller woman is losing a significant amount of fat per week and the male is dropping fat at a pretty absurd rate. As noted, for bigger people, the numbers go up further and fat losses of 4-5 pounds per week are not unheard of.
Of course, a pro of that is the diet ends much more quickly than it otherwise would. A diet that might have taken 2-3 months may be compressed into a month. For some people, this is a huge pro, they can get back to serious training or what have you since the diet isn’t interrupting things for extended periods.
As well, in some situations (e.g. Class reunion, wedding 2 weeks away), people may only have a limited time to lose the maximum weight/fat possible; that requires an extreme approach because there simply isn’t time to use anything slower.
As well, for people with a large amount of weight to lose, seeing a quick initial drop can provide some nice positive reinforcement to continue with the diet. Again, someone with 50-100 pounds to lose will likely be disappointed to drop only a pound or two in the first week. A large deficit diet may generate a scale drop (and some of this is water weight) of 7-10 pounds in the first week.
This can help with long-term adherence. Even a 2-4 week period with a large deficit to get some quick initial weight/fat loss before moving into a more moderate deficit approach can be beneficial here.
And, assuming the diet is set up appropriately (adequate protein) with the right kind of training (heavy weight training as discussed in , muscle loss actually turns out to be minimal or zero. I know this runs counter to the commonly held belief but it’s 100% true (as people following my properly have demonstrated).
Certainly early research suggested that bigger deficits and very low caloric intakes led to more muscle loss but invariably they had inadequate protein and didn’t have weight training as part of the program. When someone is on 300 cal/day and half of that is carbs, well, that’s only 40 grams of protein. Of course muscle is lost, but not because calories are low per se; rather it’s because the diet is set up stupidly.
Which brings us to one of the cons: Because of the massive deficit involved, most of it almost has to come from diet. Most can’t spend the hours per day to expend the types of calories inherent to large deficit dieting so it comes down mostly to diet.
And since so few calories are being consumed, this allows for very little food flexibility. My large deficit diets always end up being high-protein, low-carb and relatively low fat because that’s the only way to achieve the necessary deficits while providing sufficient protein. There simply isn’t room for much else.
From a long-term adherence standpoint, that can be a problem. Of course, my diets also always include free meals, refeeds and diet breaks to account for that but some can go crazy with such a limited number of foods available. Then again, large deficit diets are rarely meant to be used in the long-term in the first place and often the short-period of extreme restriction seems to ‘reset’ some food issues for people. They can lose their taste for a lot of the stuff that they used to over-eat previously and that can help in the long-term.
Which brings us to the issue of adherence. Again, contrary to popular belief, as i discussed in there is actually some data suggesting better long-term weight loss with faster initial weight/fat loss.
But this is predicated on the diet being set up in certain specific ways: The diet must change long-term food patterns (meaning it should revolve around whole foods, not protein shakes), it must include exercise, it must work on behavioral aspects of eating. Not all large deficit diets are set up that way and the ones that aren’t are destined to fail. Diets based around living on shakes or what have you may generate amazing fat loss but they do nothing to help in the long-term, nothing has been changed about long-term eating habits to help the person know what to eat when the diet ends.
Of course, with a deficit that massive, it’s nearly impossible to completely offset the deficit without some pretty major screw ups in terms of food choices. Make no mistake, it can happen, people end up choosing high-protein foods that contain too many tagalong fats and carbs and this offsets the deficit. But even with that, the deficit ends up being pretty damn big and fat loss is pretty quick.
On that note, the severe restriction can be too much for people although, interestingly, many report that hunger actually isn’t a huge issue. Between the hunger blunting effect of massive amounts of protein and other issues, hunger often goes away. Odd but true and this certainly isn’t universal.
As well, long-term adherence can be an issue and returning to maintenance caloric intakes is a problem for some. This is actually a big part of why large deficit diets are best set up around whole foods. When the diet is based around protein shakes, the dieter has no idea how to ‘eat normally’ when the diet is over.