Recent studies indicate that mood disorders such as depression and anxiety can be linked to a range of physical changes in the brain, such as inflammation or change in gene expression71. Early results from animal studies have shown that ketosis could improve mood disorders, although the mechanism is still unclear. Rats fed exogenous ketones for several weeks showed reduced anxiety behaviours72. Similarly, endogenous and exogenous BHB alleviated depressive behaviour in mice subjected to stress73. This was found to be linked to altered epigenetic markers (modifications to DNA that affect the degree of gene expression) and an increased amount of brain derived neurotrophic factor (BDNF) in the brain. At this time, there are no trials investigating the effects of ketosis in human patients with mood disorders. 
The handheld devices that are available for home testing (such as FreeStyle by Abbott, or KetoMojo) require a small droplet of blood (obtained by a finger prick with a lancet) to be placed on a testing strip. A new testing strip must be used each time a reading is taken. The machine delivers a numerical blood BHB measurement in the unit milli molar (mM) after ~8 seconds. 
The secret step in this recipe that takes this carb-free bread from good to great is the separation of the eggs. You’re going to want to separate the yolks and the whites. The reason for this is that we’re going to whip the egg whites until they are fluffy. We’re looking for soft peaks. This will add some volume to the otherwise dense keto bread. Beating the egg whites is the answer to the denseness that comes with making an almond flour bread. I’ve made countless baked goods using almond flour and the main problem I’ve encountered is how dense the finished product is. The fluffy egg whites in unison with the high dosage of baking powder do a good job of getting this loaf nice and fluffy and adding some air pockets into the loaf. This makes for a better tasting bread.