There are a number of potential systems that describe why nuts may not be fattening which were explored in a recent review that appeared in the Journal of Nutrition recently.
Nuts are pleasing
Studies show that nuts tend to be helpful at satisfying the appetite, which can mean that persons just end up eating less of other foods. The percentage of calories that come from nuts that are rewarded for by eating less of other foods varies from study to study, but comes in at around 70 per cent.
Two things in the scientific literature have been identified as factors which may influence a food’s ability to satisfy the appetite: its glycaemic index (the lower, the better) and its protein content. Nuts have a low GI value and are also reasonably rich in protein, and these qualities may help to explain why they tend to be quite successful at sating the appetite.
Because nuts have a low GI, they may tend not to enhance fat storage
This system is basically not given with in the review, but Theoretically, a food will tend to cause more fat accumulation in the body if it releases sugar relatively rapidly into the bloodstream. Such foods tend to cause rises in the hormone insulin which is the primary fat storage hormone in the body. The low GI nature of nuts may as a result help to account for why it is that this food does not appear to be particularly fattening.
Nuts can stimulate the metabolism
studies show that eating nuts in the long-term has beneficial effects on the metabolism: some studies show that nuts can raise the metabolic rate by more than 10 per cent.
Not all of the fat in nuts is absorbed from the stomach
Studies typically show that about 10-15 per cent of the calorific value of nuts is not absorbed by the stomach, and passes straight out of the body.
so its now accurate to state that whether someone loses, gains or maintains their weight is simply down to ‘calories in and calories out’. This, clearly, is a gross oversimplification of reality. Also, getting people focused on calories can often cause them to construct their diet that are:
- low in calories, but not particularly healthy
- don’t really satisfy the appetite very well, causing people to be starving and therefore more likely to go back to their original diet
Nuts are a prime example of why, when considering whether a food is likely to be and weight loss weight gain food, we need to go way beyond the calories it contains. The authors of the review comment: There are claims that energy-dense foods are especially tricky for weight loss and maintenance. Nuts are among the most energy-dense foods consumed, yet the literature consistently documents little impact of their ingestion on body weight. These data suggest that each food must be analyzed logically for its impact on body and weight loss weight gain total diet quality to ensure recommendations about its use is sound and empirically based.