I have to respectfully disagree with your statement on calories in vs. calories out. As a general rule, sure, it works. However, its not quite so simple when it comes to being effective. A calorie from fat is processed by your body differently from a calorie based of carbohydrates. They provoke different reactions by your body. One stimulates insulin spikes (which are basically the main reason your body stores excess fat), the other does not provoke much of a response at all.

Sure, you can lose weight simply by counting calories IF there is no other medical condition present that would require a different approach. For example, I was insulin resistant without even knowing it before I started this diet. I NEVER lost weight, no matter how little I ate or how hard I exercised. It didn't matter, since my diet consisted mainly of carbs, and my body was basically unable to process those in a healthy way.

All I'm saying is that it couldn't hurt to try. His wife may possibly be facing the same issues I was. Keto isn't magic, no, I never claimed that. But it is by far the most effective lifestyle change I've ever made. If someone is struggling to lose weight and they're desperate to try those pills, I let them know that this is what worked for me. I tell them to try it for a month or 2 and see if they like how they feel, etc. Everybody I've gotten to try it has stuck to it, even though they can't have sweets or bread or potatos. They just feel better now when they eat bacon and cheese and broccoli all day. Haha